title: Bhagat Singh

text: Singh was a prominent member of the Hindustan Republican Association (HRA) and was probably responsible, in large part, for its change of name to Hindustan Socialist Republican Association (HSRA) in 1928. The HSRA vowed to avenge Rai's death. Singh conspired with revolutionaries like Shivaram Rajguru, Sukhdev Thapar, and Chandrashekhar Azad to kill Scott. However, in a case of mistaken identity, the plotters shot John P. Saunders, an Assistant Superintendent of Police, as he was leaving the District Police Headquarters in Lahore on 17 December 1928.


title: Bhagat Singh

text: Contemporary reaction to the killing differs substantially from the adulation that later surfaced. The Naujawan Bharat Sabha, which had organised the Lahore protest march along with the HSRA, found that attendance at its subsequent public meetings dropped sharply. Politicians, activists, and newspapers, including "The People", which Rai had founded in 1925, stressed that non-co-operation was preferable to violence. The murder was condemned as a retrograde action by Mahatma Gandhi, the Congress leader, but Jawaharlal Nehru later wrote that:


title: Bhagat Singh

text: After killing Saunders, the group escaped through the D.A.V. College entrance, across the road from the District Police Headquarters. Chanan Singh, a Head Constable who was chasing them, was shot dead by Chandrashekhar Azad. They then fled on bicycles to pre-arranged safe houses. The police launched a massive search operation to catch them, blocking all entrances and exits to and from the city; the CID kept a watch on all young men leaving Lahore. The fugitives hid for the next two days. On 19 December 1928, Sukhdev called on Durgawati Devi, sometimes known as Durga Bhabhi, wife of another HSRA member, Bhagwati Charan Vohra, for help, which she agreed to provide. They decided to catch the train departing from Lahore to Bathinda en route to Howrah (Calcutta) early the next morning.


title: Bhagat Singh

text: Bhagat Singh and Rajguru, both carrying loaded revolvers, left the house early the next day. Dressed in western attire (Bhagat Singh cut his hair, shaved his beard and wore a hat over cropped hair), and carrying Devi's sleeping child, Singh and Devi passed as a young couple, while Rajguru carried their luggage as their servant. At the station, Singh managed to conceal his identity while buying tickets, and the three boarded the train heading to Cawnpore (now Kanpur). There they boarded a train for Lucknow since the CID at Howrah railway station usually scrutinised passengers on the direct train from Lahore. At Lucknow, Rajguru left separately for Benares while Singh, Devi and the infant went to Howrah, with all except Singh returning to Lahore a few days later.


title: Bhagat Singh

text: For some time, Bhagat Singh had been exploiting the power of drama as a means to inspire the revolt against the British, purchasing a magic lantern to show slides that enlivened his talks about revolutionaries such as Ram Prasad Bismil who had died as a result of the Kakori conspiracy. In 1929, he proposed a dramatic act to the HSRA intended to gain massive publicity for their aims. Influenced by Auguste Vaillant, a French anarchist who had bombed the Chamber of Deputies in Paris, Singh's plan was to explode a bomb inside the Central Legislative Assembly. The nominal intention was to protest against the Public Safety Bill, and the Trade Dispute Act, which had been rejected by the Assembly but were being enacted by the Viceroy using his special powers; the actual intention was for the perpetrators to allow themselves to be arrested so that they could use court appearances as a stage to publicise their cause.


title: Bhagat Singh

text: The HSRA leadership was initially opposed to Bhagat's participation in the bombing because they were certain that his prior involvement in the Saunders shooting meant that his arrest would ultimately result in his execution. However, they eventually decided that he was their most suitable candidate. On 8 April 1929, Singh, accompanied by Batukeshwar Dutt, threw two bombs into the Assembly chamber from its public gallery while it was in session. The bombs had been designed not to kill, but some members, including George Ernest Schuster, the finance member of the Viceroy's Executive Council, were injured. The smoke from the bombs filled the Assembly so that Singh and Dutt could probably have escaped in the confusion had they wished. Instead, they stayed shouting the slogan "Inquilab Zindabad!" ("Long Live the Revolution") and threw leaflets. The two men were arrested and subsequently moved through a series of jails in Delhi.


title: Bhagat Singh

text: According to Neeti Nair, associate professor of history, "public criticism of this terrorist action was unequivocal." Gandhi, once again, issued strong words of disapproval of their deed. Nonetheless, the jailed Bhagat was reported to be elated, and referred to the subsequent legal proceedings as a "drama". Singh and Dutt eventually responded to the criticism by writing the Assembly Bomb Statement:


title: Bhagat Singh

text: The trial began in the first week of June, following a preliminary hearing in May. On 12 June, both men were sentenced to life imprisonment for: "causing explosions of a nature likely to endanger life, unlawfully and maliciously." Dutt had been defended by Asaf Ali, while Singh defended himself. Doubts have been raised about the accuracy of testimony offered at the trial. One key discrepancy concerns the automatic pistol that Singh had been carrying when he was arrested. Some witnesses said that he had fired two or three shots while the police sergeant who arrested him testified that the gun was pointed downward when he took it from him and that Singh "was playing with it." According to an article in the "India Law Journal", the prosecution witnesses were coached, their accounts were incorrect, and Singh had turned over the pistol himself. Singh was given a life sentence.


title: Bhagat Singh

text: In 1929, the HSRA had set up bomb factories in Lahore and Saharanpur. On 15 April 1929, the Lahore bomb factory was discovered by the police, leading to the arrest of other members of HSRA, including Sukhdev, Kishori Lal, and Jai Gopal. Not long after this, the Saharanpur factory was also raided and some of the conspirators became informants. With the new information available, the police were able to connect the three strands of the Saunders murder, Assembly bombing, and bomb manufacture. Singh, Sukhdev, Rajguru, and 21 others were charged with the Saunders murder.


title: Bhagat Singh

text: Singh was re-arrested for murdering Saunders and Chanan Singh based on substantial evidence against him, including statements by his associates, Hans Raj Vohra and Jai Gopal. His life sentence in the Assembly Bomb case was deferred until the Saunders case was decided. He was sent to Central Jail Mianwali from the Delhi jail. There he witnessed discrimination between European and Indian prisoners. He considered himself, along with others, to be a political prisoner. He noted that he had received an enhanced diet at Delhi which was not being provided at Mianwali. He led other Indian, self-identified political prisoners he felt were being treated as common criminals in a hunger strike. They demanded equality in food standards, clothing, toiletries, and other hygienic necessities, as well as access to books and a daily newspaper. They argued that they should not be forced to do manual labour or any undignified work in the jail.


title: Bhagat Singh

text: The hunger strike inspired a rise in public support for Singh and his colleagues from around June 1929. "The Tribune" newspaper was particularly prominent in this movement and reported on mass meetings in places such as Lahore and Amritsar. The government had to apply Section 144 of the criminal code in an attempt to limit gatherings.


title: Bhagat Singh

text: Jawaharlal Nehru met Singh and the other strikers in Central Jail Mianwali. After the meeting, he stated:


title: Bhagat Singh

text: The government tried to break the strike by placing different food items in the prison cells to test the prisoners' resolve. Water pitchers were filled with milk so that either the prisoners remained thirsty or broke their strike; nobody faltered and the impasse continued. The authorities then attempted force-feeding the prisoners but this was resisted. With the matter still unresolved, the Indian Viceroy, Lord Irwin, cut short his vacation in Simla to discuss the situation with jail authorities. Since the activities of the hunger strikers had gained popularity and attention amongst the people nationwide, the government decided to advance the start of the Saunders murder trial, which was henceforth called the Lahore Conspiracy Case. Singh was transported to Borstal Jail, Lahore, and the trial began there on 10 July 1929. In addition to charging them with the murder of Saunders, Singh and the 27 other prisoners were charged with plotting a conspiracy to murder Scott, and waging a war against the King. Singh, still on hunger strike, had to be carried to the court handcuffed on a stretcher; he had lost from his original weight of since beginning the strike.


title: Bhagat Singh

text: The government was beginning to make concessions but refused to move on the core issue of recognising the classification of "political prisoner". In the eyes of officials, if someone broke the law then that was a personal act, not a political one, and they were common criminals. By now, the condition of another hunger striker, Jatindra Nath Das, lodged in the same jail, had deteriorated considerably. The Jail committee recommended his unconditional release, but the government rejected the suggestion and offered to release him on bail. On 13 September 1929, Das died after a 63-day hunger strike. Almost all the nationalist leaders in the country paid tribute to Das' death. Mohammad Alam and Gopi Chand Bhargava resigned from the Punjab Legislative Council in protest, and Nehru moved a successful adjournment motion in the Central Assembly as a censure against the "inhumane treatment" of the Lahore prisoners. Singh finally heeded a resolution of the Congress party, and a request by his father, ending his hunger strike on 5 October 1929 after 116 days. During this period, Singh's popularity among common Indians extended beyond Punjab.


title: Bhagat Singh

text: Singh's attention now turned to his trial, where he was to face a Crown prosecution team comprising C. H. Carden-Noad, Kalandar Ali Khan, Jai Gopal Lal, and the prosecuting inspector, Bakshi Dina Nath. The defence was composed of eight lawyers. Prem Dutt Verma, the youngest amongst the 27 accused, threw his slipper at Gopal when he turned and became a prosecution witness in court. As a result, the magistrate ordered that all the accused should be handcuffed. Singh and others refused to be handcuffed and were subjected to brutal beating. The revolutionaries refused to attend the court and Singh wrote a letter to the magistrate citing various reasons for their refusal. The magistrate ordered the trial to proceed without the accused or members of the HSRA. This was a setback for Singh as he could no longer use the trial as a forum to publicise his views.


title: Bhagat Singh

text: To speed up the slow trial, the Viceroy, Lord Irwin, declared an emergency on 1 May 1930 and introduced an ordinance to set up a special tribunal composed of three high court judges for the case. This decision cut short the normal process of justice as the only appeal after the tribunal was to the Privy Council located in England.


title: Bhagat Singh

text: On 2 July 1930, a "habeas corpus" petition was filed in the High Court challenging the ordinance on the grounds that it was "ultra vires" and, therefore, illegal; the Viceroy had no powers to shorten the customary process of determining justice. The petition argued that the Defence of India Act 1915 allowed the Viceroy to introduce an ordinance, and set up such a tribunal, only under conditions of a breakdown of law-and-order, which, it was claimed in this case, had not occurred. However, the petition was dismissed as being premature.


title: Bhagat Singh

text: Carden-Noad presented the government's charges of conducting robberies, and the illegal acquisition of arms and ammunition among others. The evidence of G. T. H. Hamilton Harding, the Lahore superintendent of police, shocked the court. He stated that he had filed the first information report against the accused under specific orders from the chief secretary to the governor of Punjab and that he was unaware of the details of the case. The prosecution depended mainly on the evidence of P. N. Ghosh, Hans Raj Vohra, and Jai Gopal who had been Singh's associates in the HSRA. On 10 July 1930, the tribunal decided to press charges against only 15 of the 18 accused and allowed their petitions to be taken up for hearing the next day. The trial ended on 30 September 1930. The three accused, whose charges were withdrawn, included Dutt who had already been given a life sentence in the Assembly bomb case.


title: Bhagat Singh

text: The ordinance (and the tribunal) would lapse on 31 October 1930 as it had not been passed by the Central Assembly or the British Parliament. On 7 October 1930, the tribunal delivered its 300-page judgement based on all the evidence and concluded that the participation of Singh, Sukhdev, and Rajguru in Saunder's murder was proven. They were sentenced to death by hanging. Of the other accused, three were acquitted (Ajoy Ghosh, Jatindra Nath Sanyal and Des Raj), Kundan Lal received seven years' rigorous imprisonment, Prem Dutt received five years of the same, and the remaining seven (Kishori Lal, Mahabir Singh, Bijoy Kumar Sinha, Shiv Verma, Gaya Prasad, Jai Dev and Kamalnath Tewari) were all sentenced to transportation for life.


title: Bhagat Singh

text: In Punjab province, a defence committee drew up a plan to appeal to the Privy Council. Singh was initially against the appeal but later agreed to it in the hope that the appeal would popularise the HSRA in Britain. The appellants claimed that the ordinance which created the tribunal was invalid while the government countered that the Viceroy was completely empowered to create such a tribunal. The appeal was dismissed by Judge Viscount Dunedin.


title: Bhagat Singh

text: After the rejection of the appeal to the Privy Council, Congress party president Madan Mohan Malaviya filed a mercy appeal before Irwin on 14 February 1931. Some prisoners sent Mahatma Gandhi an appeal to intervene. In his notes dated 19 March 1931, the Viceroy recorded:


title: Bhagat Singh

text: A plan to rescue Singh and fellow HSRA inmates from the jail failed. HSRA member Durga Devi's husband, Bhagwati Charan Vohra, attempted to manufacture bombs for the purpose, but died when they exploded accidentally.


title: Bhagat Singh

text: Singh, Rajguru and Sukhdev were sentenced to death in the Lahore conspiracy case and ordered to be hanged on 24 March 1931. The schedule was moved forward by 11 hours and the three were hanged on 23 March 1931 at 7:30 pm in the Lahore jail. It is reported that no magistrate at the time was willing to supervise Singh's hanging as was required by law. The execution was supervised instead by an honorary judge, who also signed the three death warrants, as their original warrants had expired. The jail authorities then broke a hole in the rear wall of the jail, removed the bodies, and secretly cremated the three men under cover of darkness outside Ganda Singh Wala village, and then threw the ashes into the Sutlej river, about from Ferozepore.


title: Bhagat Singh

text: Singh's trial has been described by the Supreme Court as "contrary to the fundamental doctrine of criminal jurisprudence" because there was no opportunity for the accused to defend themselves. The Special Tribunal was a departure from the normal procedure adopted for a trial and its decision could only be appealed to the Privy Council located in Britain. The accused were absent from the court and the judgement was passed ex-parte. The ordinance, which was introduced by the Viceroy to form the Special Tribunal, was never approved by the Central Assembly or the British Parliament, and it eventually lapsed without any legal or constitutional sanctity.


title: Bhagat Singh

text: The executions were reported widely by the press, especially as they took place on the eve of the annual convention of the Congress party at Karachi. Gandhi faced black flag demonstrations by angry youths who shouted "Down with Gandhi". "The New York Times" reported:


title: Bhagat Singh

text: Hartals and strikes of mourning were called. The Congress party, during the Karachi session, declared:


title: Bhagat Singh

text: There have been suggestions that Gandhi had an opportunity to stop Singh's execution but refrained from doing so. Another theory is that Gandhi actively conspired with the British to have Singh executed. In contrast, Gandhi's supporters argue that he did not have enough influence with the British to stop the execution, much less arrange it, but claim that he did his best to save Singh's life. They also assert that Singh's role in the independence movement was no threat to Gandhi's role as its leader, so he would have no reason to want him dead. Gandhi always maintained that he was a great admirer of Singh's patriotism. He also stated that he was opposed to Singh's execution (and for that matter, capital punishment in general) and proclaimed that he had no power to stop it. Of Singh's execution Gandhi said: "The government certainly had the right to hang these men. However, there are some rights which do credit to those who possess them only if they are enjoyed in name only." Gandhi also once remarked about capital punishment: "I cannot in all conscience agree to anyone being sent to the gallows. God alone can take life, because he alone gives it." Gandhi had managed to have 90,000 political prisoners, who were not members of his Satyagraha movement, released under the Gandhi–Irwin Pact. According to a report in the Indian magazine "Frontline", he did plead several times for the commutation of the death sentences of Singh, Rajguru and Sukhdev, including a personal visit on 19 March 1931. In a letter to the Viceroy on the day of their execution, he pleaded fervently for commutation, not knowing that the letter would arrive too late. Lord Irwin, the Viceroy, later said:


title: Bhagat Singh

text: Singh regarded Kartar Singh Sarabha, the founding-member of the Ghadar Party as his hero. Bhagat was also inspired by Bhai Parmanand, another founding-member of the Ghadar Party. Singh was attracted to anarchism and communism. He was an avid reader of the teachings of Mikhail Bakunin and also read Karl Marx, Vladimir Lenin and Leon Trotsky. In his last testament, "To Young Political Workers", he declares his ideal as the "Social reconstruction on new, i.e., Marxist, basis". Singh did not believe in the Gandhian ideology – which advocated Satyagraha and other forms of non-violent resistance, and felt that such politics would replace one set of exploiters with another.


title: Bhagat Singh

text: From May to September 1928, Singh published a series of articles on anarchism in "Kirti". He was concerned that the public misunderstood the concept of anarchism, writing that: "The people are scared of the word anarchism. The word anarchism has been abused so much that even in India revolutionaries have been called anarchist to make them unpopular." He clarified that anarchism refers to the absence of a ruler and abolition of the state, not the absence of order. He went on to say: "I think in India the idea of universal brotherhood, the Sanskrit sentence "Vasudhaiva Kutumbakam" etc., has the same meaning." He believed that:


title: Bhagat Singh

text: On 21 January 1930, during the trial of the Lahore Conspiracy Case, Bhagat Singh and his HSRA comrades, appeared in the court wearing red scarves. When the magistrate took his chair, they raised slogans "Long Live Socialist Revolution", "Long Live Communist International", "Long Live People" "Lenin's Name Will Never Die", and "Down with Imperialism". Bhagat Singh then read the text of a telegram in the court and asked the magistrate to send it to the Third International. The telegram stated:


title: Bhagat Singh

text: Historian K. N. Panikkar described Singh as one of the early Marxists in India. The political theorist Jason Adams notes that he was more enamoured with Lenin than with Marx. From 1926 onward, he studied the history of the revolutionary movements in India and abroad. In his prison notebooks, he quoted Lenin in reference to imperialism and capitalism and also the revolutionary thoughts of Trotsky.


title: Bhagat Singh

text: On the day his execution, Bhagat Singh was reading the book, "Reminiscences of Lenin", authored by Clara Zetkin, a German Marxist. When asked what his last wish was, Singh replied that he was studying the life of Lenin and he wanted to finish it before his death.


title: Bhagat Singh

text: Singh began to question religious ideologies after witnessing the Hindu–Muslim riots that broke out after Gandhi disbanded the Non-Cooperation Movement. He did not understand how members of these two groups, initially united in fighting against the British, could be at each other's throats because of their religious differences. At this point, Singh dropped his religious beliefs, since he believed religion hindered the revolutionaries' struggle for independence, and began studying the works of Bakunin, Lenin, Trotsky – all atheist revolutionaries. He also took an interest in Soham Swami's book "Common Sense".


title: Bhagat Singh

text: While in prison in 1930–31, Bhagat Singh was approached by Randhir Singh, a fellow inmate, and a Sikh leader who would later found the Akhand Kirtani Jatha. According to Bhagat Singh's close associate Shiva Verma, who later compiled and edited his writings, Randhir Singh tried to convince Bhagat Singh of the existence of God, and upon failing berated him: "You are giddy with fame and have developed an ego that is standing like a black curtain between you and God". In response, Bhagat Singh wrote an essay entitled "Why I Am an Atheist" to address the question of whether his atheism was born out of vanity. In the essay, he defended his own beliefs and said that he used to be a firm believer in the Almighty, but could not bring himself to believe the myths and beliefs that others held close to their hearts. He acknowledged the fact that religion made death easier, but also said that unproven philosophy is a sign of human weakness. In this context, he noted:


title: Bhagat Singh

text: In the leaflet he threw in the Central Assembly on 8 April 1929, he stated: "It is easy to kill individuals but you cannot kill the ideas. Great empires crumbled, while the ideas survived." While in prison, Singh and two others had written a letter to Lord Irwin, wherein they asked to be treated as prisoners of war and consequently to be executed by firing squad and not by hanging. Prannath Mehta, Singh's friend, visited him in the jail on 20 March, three days before his execution, with a draft letter for clemency, but he declined to sign it.


title: Bhagat Singh

text: Singh was criticised both by his contemporaries, and by people after his death, for his violent and revolutionary stance towards the British as well as his strong opposition to the pacifist stance taken by Gandhi and the Indian National Congress. The methods he used to convey his message, such as shooting Saunders, and throwing non-lethal bombs, stood in stark contrast to Gandhi's non-violent methodology, however Gandhi condemned the act of violence but he still considered him to be a great patriot and martyr.


title: Bhagat Singh

text: Subhas Chandra Bose said that: "Bhagat Singh had become the symbol of the new awakening among the youths." Nehru acknowledged that Bhagat Singh's popularity was leading to a new national awakening, saying: "He was a clean fighter who faced his enemy in the open field ... he was like a spark that became a flame in a short time and spread from one end of the country to the other dispelling the prevailing darkness everywhere". Four years after Singh's hanging, the Director of the Intelligence Bureau, Sir Horace Williamson, wrote: "His photograph was on sale in every city and township and for a time rivaled in popularity even that of Mr. Gandhi himself".


title: Bhagat Singh

text: Bhagat Singh remains a significant figure in Indian iconography to the present day. His memory, however, defies categorisation and presents problems for various groups that might try to appropriate it. Pritam Singh, a professor who has specialised in the study of federalism, nationalism and development in India, notes that


title: Bhagat Singh

text: The youth of India still draw tremendous amount of inspiration from Singh. He was voted the "Greatest Indian" in a poll by the Indian magazine "India Today" in 2008, ahead of Bose and Gandhi. During the centenary of his birth, a group of intellectuals set up an institution named Bhagat Singh Sansthan to commemorate him and his ideals. The Parliament of India paid tributes and observed silence as a mark of respect in memory of Singh on 23 March 2001 and 2005. In Pakistan, after a long-standing demand by activists from the Bhagat Singh Memorial Foundation of Pakistan, the Shadman Chowk square in Lahore, where he was hanged, was renamed as Bhagat Singh Chowk. This change was successfully challenged in a Pakistani court. On 6 September 2015, the Bhagat Singh Memorial Foundation filed a petition in the Lahore high court and again demanded the renaming of the Chowk to Bhagat Singh Chowk.


title: Bhagat Singh

text: Several films have been made portraying the life and times of Singh. The first film based on his life was "Shaheed-e-Azad Bhagat Singh" (1954) in which Prem Adeeb played the role of Singh followed by "Shaheed Bhagat Singh" (1963), starring Shammi Kapoor as Bhagat Singh, "Shaheed" (1965) in which Manoj Kumar portrayed Bhagat Singh and "Amar Shaheed Bhagat Singh" (1974) in which Som Dutt portrays Singh. Three films about Singh were released in 2002 "Shaheed-E-Azam", "" and "The Legend of Bhagat Singh" in which Singh was portrayed by Sonu Sood, Bobby Deol and Ajay Devgn respectively. "Bhagat Singh" (2002), a drama film directed by Anand Sagar and written/produced Ramanand Sagar was aired on DD National. It featured Deepak Dutta in the titular role.


title: Bhagat Singh

text: Siddharth played the role of Bhagat Singh in the 2006 film "Rang De Basanti", a film drawing parallels between revolutionaries of Bhagat Singh's era and modern Indian youth. Another similar approach was taken in the independent film, among others, Shaheed-E-Aazam (2018) where Rahul Pathak played the lead role. Gurdas Mann played the role of Singh in "Shaheed Udham Singh", a film based on life of Udham Singh while Amol Parashar portrayed Singh in Sardar Udham, another film based on Udham Singh's life. Karam Rajpal portrayed Bhagat Singh in Star Bharat's television series "Chandrashekhar", which is based on life of Chandra Shekhar Azad.


title: Bhagat Singh

text: In 2008, Nehru Memorial Museum and Library (NMML) and Act Now for Harmony and Democracy (ANHAD), a non-profit organisation, co-produced a 40-minute documentary on Bhagat Singh entitled "Inqilab", directed by Gauhar Raza.


title: Bhagat Singh

text: Singh, Sukhdev and Rajguru have been the inspiration for a number of plays in India and Pakistan, that continue to attract crowds.


title: Bhagat Singh

text: Although, the patriotic Hindustani songs, "Sarfaroshi Ki Tamanna" ("The desire to sacrifice") created by Bismil Azimabadi, and "Mera Rang De Basanti Chola" ("O Mother! Dye my robe the colour of spring") created by Ram Prasad Bismil, are largely associated with Singh and have been used in a number of related films.


title: Bhagat Singh

text: In 1968, a postage stamp was issued in India commemorating the 61st birth anniversary of Singh. A ₹5 coin commemorating him was released for circulation in 2012.


title: Megalodon

text: Megalodon (Otodus megalodon), meaning "big tooth", is an extinct species of mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Pliocene epochs. It was formerly thought to be a member of the family Lamnidae and a close relative of the great white shark ("Carcharodon carcharias"). However, it is now classified into the extinct family Otodontidae, which diverged from the great white shark during the Early Cretaceous.


title: Megalodon

text: While regarded as one of the largest and most powerful predators to have ever lived, the megalodon is only known from fragmentary remains, and its appearance and maximum size are uncertain. Scientists differ on whether it would have more closely resembled a stockier version of the great white shark, the whale shark ("Rhincodon typus"), the basking shark ("Cetorhinus maximus") or the sand tiger shark ("Carcharias taurus"). The most recent estimate with the least error range suggests a maximum length estimate up to , although the modal lengths are estimated at . Extrapolation from a vertebral centra with dimensions based on the great white shark suggests that a megalodon about long weighs up to , long weighs up to , and long (the maximum length) weighs up to . Extrapolating from a vertebral column and reconstructing a 3D model with dimensions based on all extant lamnid sharks suggests that a long individual may have been much larger than previous estimates, reaching an excess of in body mass; an individual of this size would have needed to consume 98,175 kcal per day. Their teeth were thick and robust, built for grabbing prey and breaking bone, and their large jaws could exert a bite force of up to .


title: Megalodon

text: Megalodon probably had a major impact on the structure of marine communities. The fossil record indicates that it had a cosmopolitan distribution. It probably targeted large prey, such as whales, seals and sea turtles. Juveniles inhabited warm coastal waters and fed on fish and small whales. Unlike the great white, which attacks prey from the soft underside, megalodon probably used its strong jaws to break through the chest cavity and puncture the heart and lungs of its prey.


title: Megalodon

text: The animal faced competition from whale-eating cetaceans, such as "Livyatan" and other macroraptorial sperm whales and possibly smaller ancestral killer whales. As the shark preferred warmer waters, it is thought that oceanic cooling associated with the onset of the ice ages, coupled with the lowering of sea levels and resulting loss of suitable nursery areas, may have also contributed to its decline. A reduction in the diversity of baleen whales and a shift in their distribution toward polar regions may have reduced megalodon's primary food source. The shark's extinction coincides with a gigantism trend in baleen whales.


title: Megalodon

text: According to Renaissance accounts, gigantic triangular fossil teeth often found embedded in rocky formations were once believed to be the petrified tongues, or glossopetrae, of dragons and snakes. This interpretation was corrected in 1667 by Danish naturalist Nicolas Steno, who recognized them as shark teeth, and famously produced a depiction of a shark's head bearing such teeth. He described his findings in the book "The Head of a Shark Dissected", which also contained an illustration of a megalodon tooth.


title: Megalodon

text: Swiss naturalist Louis Agassiz gave this shark its initial scientific name, "Carcharodon megalodon", in his 1843 work "Recherches sur les poissons fossiles", based on tooth remains. English paleontologist Edward Charlesworth in his 1837 paper used the name "Carcharias megalodon", while citing Agassiz as the author, indicating that Agassiz described the species prior to 1843. English paleontologist Charles Davies Sherborn in 1928 listed an 1835 series of articles by Agassiz as the first scientific description of the shark. The specific name "megalodon" translates to "big tooth", from and ὀδούς ("odoús"), "tooth". The teeth of megalodon are morphologically similar to those of the great white shark ("Carcharodon carcharias"), and on the basis of this observation, Agassiz assigned megalodon to the genus "Carcharodon".


title: Megalodon

text: While the earliest megalodon remains have been reported from the Late Oligocene, around 28 million years ago (Mya), there is disagreement as to when it appeared, with dates ranging to as young as 16 mya. It has been thought that megalodon became extinct around the end of the Pliocene, about 2.6 Mya; claims of Pleistocene megalodon teeth, younger than 2.6 million years old, are considered unreliable. A 2019 assessment moves the extinction date back to earlier in the Pliocene, 3.6 Mya.


title: Megalodon

text: Megalodon is now considered to be a member of the family Otodontidae, genus "Otodus", as opposed to its previous classification into Lamnidae, genus "Carcharodon". Megalodon's classification into "Carcharodon" was due to dental similarity with the great white shark, but most authors currently believe that this is due to convergent evolution. In this model, the great white shark is more closely related to the extinct broad-toothed mako ("Isurus hastalis") than to megalodon, as evidenced by more similar dentition in those two sharks; megalodon teeth have much finer serrations than great white shark teeth. The great white shark is more closely related to the mako shark ("Isurus" spp.), with a common ancestor around 4 Mya. Proponents of the former model, wherein megalodon and the great white shark are more closely related, argue that the differences between their dentition are minute and obscure.


title: Megalodon

text: The genus "Carcharocles" currently contains four species: "C. auriculatus", "C. angustidens", "C. chubutensis", and "C. megalodon". The evolution of this lineage is characterized by the increase of serrations, the widening of the crown, the development of a more triangular shape, and the disappearance of the lateral cusps. The evolution in tooth morphology reflects a shift in predation tactics from a tearing-grasping bite to a cutting bite, likely reflecting a shift in prey choice from fish to cetaceans. Lateral cusplets were finally lost in a gradual process that took roughly 12 million years during the transition between "C. chubutensis" and "C. megalodon". The genus was proposed by D. S. Jordan and H. Hannibal in 1923 to contain "C. auriculatus". In the 1980s, megalodon was assigned to "Carcharocles". Before this, in 1960, the genus "Procarcharodon" was erected by French ichthyologist Edgard Casier, which included those four sharks and was considered separate from the great white shark. It is now considered a junior synonym of "Carcharocles". The genus "Palaeocarcharodon" was erected alongside "Procarcharodon" to represent the beginning of the lineage, and, in the model wherein megalodon and the great white shark are closely related, their last common ancestor. It is believed to be an evolutionary dead-end and unrelated to the "Carcharocles" sharks by authors who reject that model.


title: Megalodon

text: Another model of the evolution of this genus, also proposed by Casier in 1960, is that the direct ancestor of the "Carcharocles" is the shark "Otodus obliquus", which lived from the Paleocene through the Miocene epochs, 60 to 13 Mya. The genus "Otodus" is ultimately derived from "Cretolamna", a shark from the Cretaceous period. In this model, "O. obliquus" evolved into "O. aksuaticus", which evolved into "C. auriculatus", and then into "C. angustidens", and then into "C. chubutensis", and then finally into "C. megalodon".


title: Megalodon

text: Another model of the evolution of "Carcharocles", proposed in 2001 by paleontologist Michael Benton, is that the three other species are actually a single species of shark that gradually changed over time between the Paleocene and the Pliocene, making it a chronospecies. Some authors suggest that "C. auriculatus", "C. angustidens", and "C. chubutensis" should be classified as a single species in the genus "Otodus", leaving "C. megalodon" the sole member of "Carcharocles".


title: Megalodon

text: The genus "Carcharocles" may be invalid, and the shark may actually belong in the genus "Otodus", making it "Otodus megalodon". A 1974 study on Paleogene sharks by Henri Cappetta erected the subgenus "Megaselachus", classifying the shark as "Otodus" ("Megaselachus") "megalodon", along with "O. (M.) chubutensis". A 2006 review of Chondrichthyes elevated "Megaselachus" to genus, and classified the sharks as "Megaselachus megalodon" and "M. chubutensis". The discovery of fossils assigned to the genus "Megalolamna" in 2016 led to a re-evaluation of "Otodus", which concluded that it is paraphyletic, that is, it consists of a last common ancestor but it does not include all of its descendants. The inclusion of the "Carcharocles" sharks in "Otodus" would make it monophyletic, with the sister clade being "Megalolamna".


title: Megalodon

text: The cladogram below represents the hypothetical relationships between megalodon and other sharks, including the great white shark. Modified from Shimada et al. (2016), Ehret et al, (2009), and the findings of Siversson et al. (2013).


title: Megalodon

text: One interpretation on how megalodon appeared was that it was a robust-looking shark, and may have had a similar build to the great white shark. The jaws may have been blunter and wider than the great white, and the fins would have also been similar in shape, though thicker due to its size. It may have had a pig-eyed appearance, in that it had small, deep-set eyes.


title: Megalodon

text: Another interpretation is that megalodon bore a similarity to the whale shark ("Rhincodon typus") or the basking shark ("Cetorhinus maximus"). The tail fin would have been crescent-shaped, the anal fin and second dorsal fin would have been small, and there would have been a caudal keel present on either side of the tail fin (on the caudal peduncle). This build is common in other large aquatic animals, such as whales, tuna, and other sharks, in order to reduce drag while swimming. The head shape can vary between species as most of the drag-reducing adaptations are toward the tail-end of the animal.


title: Megalodon

text: Since "Carcharocles" is derived from "Otodus", and the two had teeth that bear a close similarity to those of the sand tiger shark ("Carcharias taurus"), megalodon may have had a build more similar to the sand tiger shark than to other sharks. This is unlikely since the sand tiger shark is a carangiform swimmer which requires faster movement of the tail for propulsion through the water than the great white shark, a thunniform swimmer.


title: Megalodon

text: Due to fragmentary remains, there have been many contradictory size estimates for megalodon, as they can only be drawn from fossil teeth and vertebrae. The great white shark has been the basis of reconstruction and size estimation, as it is regarded as the best analogue to megalodon. Several total length estimation methods have been produced from comparing megalodon teeth and vertebrae to those of the great white.


title: Megalodon

text: Megalodon size estimates vary depending on the method used, with maximum total length estimates ranging from . A 2015 study estimated the average total body length at , calculated from 544 megalodon teeth, found throughout geological time and geography, including adults and juveniles. In comparison, large great white sharks are generally around in length, with a few contentious reports suggesting larger sizes. The whale shark is the largest living fish, with one large female reported with a precaudal length of and an estimated total length of . It is possible that different populations of megalodon around the globe had different body sizes and behaviors due to different ecological pressures. Megalodon is thought to have been the largest macropredatory shark that ever lived.


title: Megalodon

text: In his 2015 book, "The Story of Life in 25 Fossils: Tales of Intrepid Fossil Hunters and the Wonders of Evolution", Donald Prothero proposed the body mass estimates for different individiuals of different length by extrapolating from a vertebral centra based on the dimensions of the great white, a methodology also used for the 2008 study which supports the maximum mass estimate.


title: Megalodon

text: In 2020, Cooper and his colleagues reconstructed a 2D model of megalodon based on the dimensions of all the extant lamnid sharks and suggested that a long megalodon would have had a long head, tall gill slits, a tall dorsal fin, long pectoral fins, and a tall tail fin. In 2022, Cooper and his colleagues also reconstructed a 3D model with the same basis as the 2020 study, resulting in a body mass estimate of for a long megalodon (higher than the previous estimates); a vertebral column specimen named IRSNB P 9893 (formerly IRSNB 3121), belonging to a 46 year old individual from Belgium, was used for extrapolation. An individual of this size would have required 98,175 kcal per day, 20 times more than what the adult great white requires.


title: Megalodon

text: Mature male megalodon may have had a body mass of , and mature females may have been , assuming that males could range in length from and females .


title: Megalodon

text: A 2015 study linking shark size and typical swimming speed estimated that megalodon would have typically swum at –assuming that its body mass was typically –which is consistent with other aquatic creatures of its size, such as the fin whale ("Balaenoptera physalus") which typically cruises at speeds of . In 2022, Cooper and his colleagues converted this calculation into relative cruising speed (body lengths per second), resulting in an mean absolute crusing speed of and a mean relative cruising speed of 0.09 body lengths per second for a long megalodon; the authors found their mean absolute cruising speed to be faster than any extant lamnid sharks and their mean relative cruising speed to be slower, consistent with previous estiamtes.


title: Megalodon

text: Its large size may have been due to climatic factors and the abundance of large prey items, and it may have also been influenced by the evolution of regional endothermy (mesothermy) which would have increased its metabolic rate and swimming speed. The otodontid sharks have been considered to have been ectotherms, so on that basis megalodon would have been ectothermic. However, the largest contemporary ectothermic sharks, such as the whale shark, are filter feeders, while lamnids are now known to be regional endotherms, implying some metabolic correlations with a predatory lifestyle. These considerations, as well as tooth oxygen isotopic data and the need for higher burst swimming speeds in macropredators of endothermic prey than ectothermy would allow, imply that otodontids, including megalodon, were probably regional endotherms.


title: Megalodon

text: In 2020, Shimada and colleagues suggested large size was instead due to intrauterine cannibalism, where the larger fetus eats the smaller fetus, resulting in progressively larger and larger fetuses, requiring the mother to attain even greater size as well as caloric requirements which would have promoted endothermy. Males would have needed to keep up with female size in order to still effectively copulate (which probably involved latching onto the female with claspers, like modern cartilaginous fish).


title: Megalodon

text: The first attempt to reconstruct the jaw of megalodon was made by Bashford Dean in 1909, displayed at the American Museum of Natural History. From the dimensions of this jaw reconstruction, it was hypothesized that megalodon could have approached in length. Dean had overestimated the size of the cartilage on both jaws, causing it to be too tall.


title: Megalodon

text: In 1973, John E. Randall, an ichthyologist, used the enamel height (the vertical distance of the blade from the base of the enamel portion of the tooth to its tip) to measure the length of the shark, yielding a maximum length of about . However, tooth enamel height does not necessarily increase in proportion to the animal's total length.


title: Megalodon

text: In 1994, marine biologists Patrick J. Schembri and Stephen Papson opined that "O. megalodon" may have approached a maximum of around in total length.


title: Megalodon

text: In 1996, shark researchers Michael D. Gottfried, Leonard Compagno, and S. Curtis Bowman proposed a linear relationship between the great white shark's total length and the height of the largest upper anterior tooth. The proposed relationship is: total length in meters = − (0.096) × [UA maximum height (mm)]-(0.22). Using this tooth height regression equation, the authors estimated a total length of based on a tooth tall, which the authors considered a conservative maximum estimate. They also compared the ratio between the tooth height and total length of large female great whites to the largest megalodon tooth. A long female great white, which the authors considered the largest 'reasonably trustworthy' total length, produced an estimate of . However, based on the largest female great white reported, at , they estimated a maximum estimate of .


title: Megalodon

text: In 2002, shark researcher Clifford Jeremiah proposed that total length was proportional to the root width of an upper anterior tooth. He claimed that for every of root width, there are approximately of shark length. Jeremiah pointed out that the jaw perimeter of a shark is directly proportional to its total length, with the width of the roots of the largest teeth being a tool for estimating jaw perimeter. The largest tooth in Jeremiah's possession had a root width of about , which yielded in total length.


title: Megalodon

text: In 2002, paleontologist Kenshu Shimada of DePaul University proposed a linear relationship between tooth crown height and total length after conducting anatomical analysis of several specimens, allowing any sized tooth to be used. Shimada stated that the previously proposed methods were based on a less-reliable evaluation of the dental homology between megalodon and the great white shark, and that the growth rate between the crown and root is not isometric, which he considered in his model. Using this model, the upper anterior tooth possessed by Gottfried and colleagues corresponded to a total length of . Among several specimens found in the Gatún Formation of Panama, one upper lateral tooth was used by other researchers to obtain a total length estimate of using this method.


title: Megalodon

text: In 2019, Shimada revisited the size of megalodon and discouraged using non-anterior teeth for estimations, noting that the exact position of isolated non-anterior teeth is difficult to identify. Shimada provided maximum total length estimates using the largest anterior teeth available in museums. The tooth with the tallest crown height known to Shimada, NSM PV-19896, produced a total length estimate of . The tooth with the tallest total height, FMNH PF 11306, was reported at . However, Shimada remeasured the tooth and found it actually to measure . Using the total height tooth regression equation proposed by Gottfried and colleagues produced an estimate of .


title: Megalodon

text: In 2021, Victor J. Perez, Ronny M. Leder, and Teddy Badaut proposed a method of estimating total length of megalodon from the sum of the tooth crown widths. Using more complete megalodon dentitions, they reconstructed the dental formula and then made comparisons to living sharks. The researchers noted that the 2002 Shimada crown height equations produce wildly varying results for different teeth belonging to the same shark (range of error of ± ), casting doubt on some of the conclusions of previous studies using that method. Using the largest tooth available to the authors, GHC 6, with a crown width of , they estimated a maximum body length of approximately , with a range of error of approximately ± . This maximum length estimate was also supported by Cooper and his colleagues in 2022.


title: Megalodon

text: There are anecdotal reports of teeth larger than those found in museum collections. Gordon Hubbell from Gainesville, Florida, possesses an upper anterior megalodon tooth whose maximum height is , one of the largest known tooth specimens from the shark. In addition, a megalodon jaw reconstruction developed by fossil hunter Vito Bertucci contains a tooth whose maximum height is reportedly over .


title: Megalodon

text: The most common fossils of megalodon are its teeth. Diagnostic characteristics include a triangular shape, robust structure, large size, fine serrations, a lack of lateral denticles, and a visible V-shaped neck (where the root meets the crown). The tooth met the jaw at a steep angle, similar to the great white shark. The tooth was anchored by connective tissue fibers, and the roughness of the base may have added to mechanical strength. The lingual side of the tooth, the part facing the tongue, was convex; and the labial side, the other side of the tooth, was slightly convex or flat. The anterior teeth were almost perpendicular to the jaw and symmetrical, whereas the posterior teeth were slanted and asymmetrical.


title: Megalodon

text: Megalodon teeth can measure over in slant height (diagonal length) and are the largest of any known shark species, implying it was the largest of all macropredatory sharks. In 1989, a nearly complete set of megalodon teeth was discovered in Saitama, Japan. Another nearly complete associated megalodon dentition was excavated from the Yorktown Formations in the United States, and served as the basis of a jaw reconstruction of megalodon at the National Museum of Natural History (USNM). Based on these discoveries, an artificial dental formula was put together for megalodon in 1996.


title: Megalodon

text: The dental formula of megalodon is: . As evident from the formula, megalodon had four kinds of teeth in its jaws: anterior, intermediate, lateral, and posterior. Megalodon's intermediate tooth technically appears to be an upper anterior and is termed as "A3" because it is fairly symmetrical and does not point mesially (side of the tooth toward the midline of the jaws where the left and right jaws meet). Megalodon had a very robust dentition, and had over 250 teeth in its jaws, spanning 5 rows. It is possible that large megalodon individuals had jaws spanning roughly across. The teeth were also serrated, which would have improved efficiency in cutting through flesh or bone. The shark may have been able to open its mouth to a 75° angle, though a reconstruction at the USNM approximates a 100° angle.


title: Megalodon

text: In 2008, a team of scientists led by S. Wroe conducted an experiment to determine the bite force of the great white shark, using a long specimen, and then isometrically scaled the results for its maximum size and the conservative minimum and maximum body mass of megalodon. They placed the bite force of the latter between in a posterior bite, compared to the bite force for the largest confirmed great white shark, and for the placoderm fish "Dunkleosteus". In addition, Wroe and colleagues pointed out that sharks shake sideways while feeding, amplifying the force generated, which would probably have caused the total force experienced by prey to be higher than the estimate.


title: Megalodon

text: In 2021, Antonio Ballell and Humberto Ferrón used Finite Element Analysis modeling to examine the stress distribution of three types of megalodon teeth and closely related mega-toothed species when exposed to anterior and lateral forces, the latter of which would be generated when a shark shakes its head to tear through flesh. The resulting simulations identified higher levels of stress in megalodon teeth under lateral force loads compared to its precursor species such as "O. obliquus" and "O. angusteidens" when tooth size was removed as a factor. This suggests that megalodon teeth were of a different functional significance than previously expected, challenging prior interpretations that megalodon's dental morphology was primarily driven by a dietary shift towards marine mammals. Instead, the authors proposed that it was a byproduct of an increase in body size caused by heterochronic selection.


title: Megalodon

text: Megalodon is represented in the fossil record by teeth, vertebral centra, and coprolites. As with all sharks, the skeleton of megalodon was formed of cartilage rather than bone; consequently most fossil specimens are poorly preserved. To support its large dentition, the jaws of megalodon would have been more massive, stouter, and more strongly developed than those of the great white, which possesses a comparatively gracile dentition. Its chondrocranium, the cartilaginous skull, would have had a blockier and more robust appearance than that of the great white. Its fins were proportional to its larger size.


title: Megalodon

text: Some fossil vertebrae have been found. The most notable example is a partially preserved vertebral column of a single specimen, excavated in the Antwerp Basin, Belgium, in 1926. It comprises 150 vertebral centra, with the centra ranging from to in diameter. The shark's vertebrae may have gotten much bigger, and scrutiny of the specimen revealed that it had a higher vertebral count than specimens of any known shark, possibly over 200 centra; only the great white approached it. Another partially preserved vertebral column of a megalodon was excavated from the Gram Formation in Denmark in 1983, which comprises 20 vertebral centra, with the centra ranging from to in diameter.


title: Megalodon

text: The coprolite remains of megalodon are spiral-shaped, indicating that the shark may have had a spiral valve, a corkscrew-shaped portion of the lower intestines, similar to extant lamniform sharks. Miocene coprolite remains were discovered in Beaufort County, South Carolina, with one measuring .


title: Megalodon

text: Gottfried and colleagues reconstructed the entire skeleton of megalodon, which was later put on display at the Calvert Marine Museum in the United States and the Iziko South African Museum. This reconstruction is long and represents a mature male, based on the ontogenetic changes a great white shark experiences over the course of its life.


title: Megalodon

text: Megalodon had a cosmopolitan distribution; its fossils have been excavated from many parts of the world, including Europe, Africa, the Americas, and Australia. It most commonly occurred in subtropical to temperate latitudes. It has been found at latitudes up to 55° N; its inferred tolerated temperature range was . It arguably had the capacity to endure such low temperatures due to mesothermy, the physiological capability of large sharks to maintain a higher body temperature than the surrounding water by conserving metabolic heat.


title: Megalodon

text: Megalodon inhabited a wide range of marine environments (i.e., shallow coastal waters, areas of coastal upwelling, swampy coastal lagoons, sandy littorals, and offshore deep water environments), and exhibited a transient lifestyle. Adult megalodon were not abundant in shallow water environments, and mostly inhabited offshore areas. Megalodon may have moved between coastal and oceanic waters, particularly in different stages of its life cycle.


title: Megalodon

text: Fossil remains show a trend for specimens to be larger on average in the Southern Hemisphere than in the Northern, with mean lengths of , respectively; and also larger in the Pacific than the Atlantic, with mean lengths of respectively. They do not suggest any trend of changing body size with absolute latitude, or of change in size over time (although the "Carcharocles" lineage in general is thought to display a trend of increasing size over time). The overall modal length has been estimated at , with the length distribution skewed towards larger individuals, suggesting an ecological or competitive advantage for larger body size.


title: Megalodon

text: Megalodon had a global distribution and fossils of the shark have been found in many places around the world, bordering all oceans of the Neogene.


title: Megalodon

text: Though sharks are generally opportunistic feeders, megalodon's great size, high-speed swimming capability, and powerful jaws, coupled with an impressive feeding apparatus, made it an apex predator capable of consuming a broad spectrum of animals. Otodus megalodon was probably one of the most powerful predators to have existed. A study focusing on calcium isotopes of extinct and extant elasmobranch sharks and rays revealed that megalodon fed at a higher trophic level than the contemporaneous great white shark ("higher up" in the food chain.)


title: Megalodon

text: Fossil evidence indicates that megalodon preyed upon many cetacean species, such as dolphins, small whales, cetotheres, squalodontids (shark toothed dolphins), sperm whales, bowhead whales, and rorquals. In addition to this, they also targeted seals, sirenians, and sea turtles. The shark was an opportunist and piscivorous, and it would have also gone after smaller fish and other sharks. Many whale bones have been found with deep gashes most likely made by their teeth. Various excavations have revealed megalodon teeth lying close to the chewed remains of whales, and sometimes in direct association with them.


title: Megalodon

text: The feeding ecology of megalodon appears to have varied with age and between sites, like the modern great white shark. It is plausible that the adult megalodon population off the coast of Peru targeted primarily cetothere whales in length and other prey smaller than itself, rather than large whales in the same size class as themselves. Meanwhile, juveniles likely had a diet that consisted more of fish.


title: Megalodon

text: Megalodon faced a highly competitive environment. Its position at the top of the food chain probably had a significant impact on the structuring of marine communities. Fossil evidence indicates a correlation between megalodon and the emergence and diversification of cetaceans and other marine mammals. Juvenile megalodon preferred habitats where small cetaceans were abundant, and adult megalodon preferred habitats where large cetaceans were abundant. Such preferences may have developed shortly after they appeared in the Oligocene.


title: Megalodon

text: Megalodon were contemporaneous with whale-eating toothed whales (particularly macroraptorial sperm whales and squalodontidae), which were also probably among the era's apex predators, and provided competition. Some attained gigantic sizes, such as "Livyatan", estimated between . Fossilized teeth of an undetermined species of such physeteroids from Lee Creek Mine, North Carolina, indicate it had a maximum body length of 8–10 m and a maximum lifespan of about 25 years. This is very different from similarly sized modern killer whales that live to 65 years, suggesting that unlike the latter, which are apex predators, these physeteroids were subject to predation from larger species such as megalodon or "Livyatan". By the Late Miocene, around 11 Mya, macroraptorials experienced a significant decline in abundance and diversity. Other species may have filled this niche in the Pliocene, such as the fossil killer whale "Orcinus citoniensis" which may have been a pack predator and targeted prey larger than itself, but this inference is disputed, and it was probably a generalist predator rather than a marine mammal specialist.


title: Megalodon

text: Megalodon may have subjected contemporaneous white sharks to competitive exclusion, as the fossil records indicate that other shark species avoided regions it inhabited by mainly keeping to the colder waters of the time. In areas where their ranges seemed to have overlapped, such as in Pliocene Baja California, it is possible that megalodon and the great white shark occupied the area at different times of the year while following different migratory prey. Megalodon probably also had a tendency for cannibalism, much like contemporary sharks.


title: Megalodon

text: Sharks often employ complex hunting strategies to engage large prey animals. Great white shark hunting strategies may be similar to how megalodon hunted its large prey. Megalodon bite marks on whale fossils suggest that it employed different hunting strategies against large prey than the great white shark.


title: Megalodon

text: One particular specimen–the remains of a long undescribed Miocene baleen whale–provided the first opportunity to quantitatively analyze its attack behavior. Unlike great whites which target the underbelly of their prey, megalodon probably targeted the heart and lungs, with their thick teeth adapted for biting through tough bone, as indicated by bite marks inflicted to the rib cage and other tough bony areas on whale remains. Furthermore, attack patterns could differ for prey of different sizes. Fossil remains of some small cetaceans, for example cetotheres, suggest that they were rammed with great force from below before being killed and eaten, based on compression fractures.


title: Megalodon

text: There is also evidence that a possible separate hunting strategy existed for attacking raptorial sperm whales; a tooth belonging to an undetermined physeteroid closely resembling those of "Acrophyseter" discovered in the Nutrien Aurora Phosphate Mine in North Carolina suggests that a megalodon or "O. chubutensis" may have aimed for the head of the sperm whale in order to inflict a fatal bite, the resulting attack leaving distinctive bite marks on the tooth. While scavenging behavior cannot be ruled out as a possibility, the placement of the bite marks is more consistent with predatory attacks than feeding by scavenging, as the jaw is not a particularly nutritious area to for a shark feed or focus on. The fact that the bite marks were found on the tooth's roots further suggest that the shark broke the whale's jaw during the bite, suggesting the bite was extremely powerful. The fossil is also notable as it stands as the first known instance of an antagonistic interaction between a sperm whale and an otodontid shark recorded in the fossil record.


title: Megalodon

text: During the Pliocene, larger cetaceans appeared. Megalodon apparently further refined its hunting strategies to cope with these large whales. Numerous fossilized flipper bones and tail vertebrae of large whales from the Pliocene have been found with megalodon bite marks, which suggests that megalodon would immobilize a large whale before killing and feeding on it.


title: Megalodon

text: In 2021, Shimada and colleagues calculated the growth rate of an approximately individual based on the Belgian vertebrate column specimen that presumably contains annual growth rings on three of its vertebrae. They estimated the individual died at 46 years of age, with a growth rate of per year, and a length of at birth. For a individual—which they considered to have been the maximum size attainable—this would equate to a lifespan of 88 to 100 years. However, Cooper and his colleagues in 2022 estimated the length of this 46 year old individual at nearly based on the 3D reconstruction which resulted in the complete vertebral column to be long; the researchers claimed that this size estimate difference occurred due to the fact that Shimada and his colleagues extrapolated its size only based on the vertebral centra.


title: Megalodon

text: Megalodon, like contemporaneous sharks, made use of nursery areas to birth their young in, specifically warm-water coastal environments with large amounts of food and protection from predators. Nursery sites were identified in the Gatún Formation of Panama, the Calvert Formation of Maryland, Banco de Concepción in the Canary Islands, and the Bone Valley Formation of Florida. Given that all extant lamniform sharks give birth to live young, this is believed to have been true of megalodon also. Infant megalodons were around at their smallest, and the pups were vulnerable to predation by other shark species, such as the great hammerhead shark ("Sphyrna mokarran") and the snaggletooth shark ("Hemipristis serra"). Their dietary preferences display an ontogenetic shift: Young megalodon commonly preyed on fish, sea turtles, dugongs, and small cetaceans; mature megalodon moved to off-shore areas and consumed large cetaceans.


title: Megalodon

text: An exceptional case in the fossil record suggests that juvenile megalodon may have occasionally attacked much larger balaenopterid whales. Three tooth marks apparently from a long Pliocene shark were found on a rib from an ancestral blue or humpback whale that showed evidence of subsequent healing, which is suspected to have been inflicted by a juvenile megalodon.


title: Megalodon

text: The Earth experienced a number of changes during the time period megalodon existed which affected marine life. A cooling trend starting in the Oligocene 35 Mya ultimately led to glaciation at the poles. Geological events changed currents and precipitation; among these were the closure of the Central American Seaway and changes in the Tethys Ocean, contributing to the cooling of the oceans. The stalling of the Gulf Stream prevented nutrient-rich water from reaching major marine ecosystems, which may have negatively affected its food sources. The largest fluctuation of sea levels in the Cenozoic era occurred in the Plio-Pleistocene, between around 5 million to 12 thousand years ago, due to the expansion of glaciers at the poles, which negatively impacted coastal environments, and may have contributed to its extinction along with those of several other marine megafaunal species. These oceanographic changes, in particular the sea level drops, may have restricted many of the suitable shallow warm-water nursery sites for megalodon, hindering reproduction. Nursery areas are pivotal for the survival of many shark species, in part because they protect juveniles from predation.


title: Megalodon

text: As its range did not apparently extend into colder waters, megalodon may not have been able to retain a significant amount of metabolic heat, so its range was restricted to shrinking warmer waters. Fossil evidence confirms the absence of megalodon in regions around the world where water temperatures had significantly declined during the Pliocene. However, an analysis of the distribution of megalodon over time suggests that temperature change did not play a direct role in its extinction. Its distribution during the Miocene and Pliocene did not correlate with warming and cooling trends; while abundance and distribution declined during the Pliocene, megalodon did show a capacity to inhabit colder latitudes. It was found in locations with a mean temperature ranging from , with a total range of , indicating that the global extent of suitable habitat should not have been greatly affected by the temperature changes that occurred. This is consistent with evidence that it was a mesotherm.


title: Megalodon

text: Marine mammals attained their greatest diversity during the Miocene, such as with baleen whales with over 20 recognized Miocene genera in comparison to only six extant genera. Such diversity presented an ideal setting to support a super-predator such as megalodon. By the end of the Miocene, many species of mysticetes had gone extinct; surviving species may have been faster swimmers and thus more elusive prey. Furthermore, after the closure of the Central American Seaway, tropical whales decreased in diversity and abundance. The extinction of megalodon correlates with the decline of many small mysticete lineages, and it is possible that it was quite dependent on them as a food source. Additionally, a marine megafauna extinction during the Pliocene was discovered to have eliminated 36% of all large marine species including 55% of marine mammals, 35% of seabirds, 9% of sharks, and 43% of sea turtles. The extinction was selective for endotherms and mesotherms relative to poikilotherms, implying causation by a decreased food supply and thus consistent with megalodon being mesothermic. Megalodon may have been too large to sustain itself on the declining marine food resources. The cooling of the oceans during the Pliocene might have restricted the access of megalodon to the polar regions, depriving it of the large whales which had migrated there.


title: Megalodon

text: Competition from large odontocetes, such as macropredatory sperm whales which appeared in the Miocene, and a member of genus "Orcinus" (i.e., "Orcinus citoniensis") in the Pliocene, is assumed to have contributed to the decline and extinction of megalodon. But this assumption is disputed: The Orcininae emerged in Mid-Pliocene with "O. citoniensis" reported from the


title: Megalodon

text: Pliocene of Italy, and similar forms reported from the Pliocene of England and South Africa, indicating the capacity of these dolphins to cope with increasingly prevalent cold water temperatures in high latitudes. These dolphins were assumed to have been macrophagous in some studies, but on closer inspection, these dolphins are not found to be macrophagous and fed on small fishes instead. On the other hand, gigantic macropredatory sperm whales such as "Livyatan"-like forms are last reported from Australia and South Africa circa 5 million years ago. Others, such as "Hoplocetus" and "Scaldicetus" also occupied a niche similar to that of modern killer whales but the last of these forms disappeared during the Pliocene. Members of genus "Orcinus" became large and macrophagous in the Pleistocene.


title: Megalodon

text: Paleontologist Robert Boessenecker and his colleagues rechecked the fossil record of megalodon for carbon dating errors and concluded that it disappeared circa 3.5 million years ago. Boessenecker and his colleagues further suggest that megalodon suffered range fragmentation due to climatic shifts, and competition with white sharks might have contributed to its decline and extinction. Competition with white sharks is assumed to be a factor in other studies as well, but this hypothesis warrants further testing. Multiple compounding environmental and ecological factors including climate change and thermal limitations, collapse of prey populations and resource competition with white sharks are believed to have contributed to decline and extinction of megalodon for now.


title: Megalodon

text: The extinction of megalodon set the stage for further changes in marine communities. The average body size of baleen whales increased significantly after its disappearance, although possibly due to other, climate-related, causes. Conversely the increase in baleen whale size may have contributed to the extinction of megalodon, as they may have preferred to go after smaller whales; bite marks on large whale species may have come from scavenging sharks. Megalodon may have simply become coextinct with smaller whale species, such as "Piscobalaena nana". The extinction of megalodon had a positive impact on other apex predators of the time, such as the great white shark, in some cases spreading to regions where megalodon became absent.


title: Megalodon

text: Megalodon has been portrayed in many works of fiction, including films and novels, and continues to be a popular subject for fiction involving sea monsters. Reports of supposedly fresh megalodon teeth, such as those found by in 1873 which were dated in 1959 by the zoologist Wladimir Tschernezky to be around 11,000 to 24,000 years old, helped popularise claims of recent megalodon survival amongst cryptozoologists. These claims are now discredited, and are probably teeth that were well-preserved by a thick mineral-crust precipitate of manganese dioxide, and so had a lower decomposition rate and retained a white color during fossilization. Fossil megalodon teeth can vary in color from off-white to dark browns and greys, and some fossil teeth may have been redeposited into a younger stratum. The claims that megalodon could remain elusive in the depths, similar to the megamouth shark which was discovered in 1976, are unlikely as the shark lived in warm coastal waters and probably could not survive in the cold and nutrient-poor deep sea environment.


title: Megalodon

text: Contemporary fiction about megalodon surviving into modern times was pioneered by the 1997 novel "" by Steve Alten and its subsequent sequels. Megalodon subsequently began to feature in films, such as the 2003 direct to video "", and later "The Meg," a 2018 film based on the 1997 book which grossed over $500 million at the box office.


title: Megalodon

text: Animal Planet's pseudo-documentary "" included an encounter 1.6 mya between a pod of mermaids and a megalodon. Later, in August 2013, the Discovery Channel opened its annual Shark Week series with another film for television, "", a controversial docufiction about the creature that presented alleged evidence in order to suggest that megalodon was still alive. This program received criticism for being completely fictional and for inadequately disclosing its fictional nature; for example, all of the supposed scientists depicted were paid actors, and there was no disclosure in the documentary itself that it was fictional. In a poll by Discovery, 73% of the viewers of the documentary thought that megalodon was not extinct. In 2014, Discovery re-aired "The Monster Shark Lives", along with a new one-hour program, "Megalodon: The New Evidence", and an additional fictionalized program entitled "Shark of Darkness: Wrath of Submarine", resulting in further backlash from media sources and the scientific community. Despite the criticism from scientists, "Megalodon: The Monster Shark Lives" was a huge ratings success, gaining 4.8 million viewers, the most for any Shark Week episode up to that point.


title: Alprazolam

text: Alprazolam, sold under the brand name Xanax, among others, is a fast-acting, potent tranquilizer of medium duration in the triazolobenzodiazepine (TBZD) class, which are benzodiazepines (BZDs) fused with a triazole ring. It is most commonly used in management of anxiety disorders, specifically panic disorder or generalized anxiety disorder (GAD). Other uses include the treatment of chemotherapy-induced nausea, together with other treatments. GAD improvement occurs generally within a week. Alprazolam is generally taken by mouth.


title: Alprazolam

text: Common side effects include sleepiness, depression, headaches, feeling tired, dry mouth, and memory problems. Some of the sedation and tiredness may improve within a few days. Withdrawal or rebound symptoms may occur if use is suddenly decreased; gradually decreasing the dose over weeks or months may be required. Other rare risks include suicide and a twofold increased risk of all-cause mortality. Alprazolam, like other benzodiazepines, acts through the GABA receptor.


title: Alprazolam

text: Alprazolam is mostly used in management of anxiety disorders, panic disorders, and nausea due to chemotherapy. Alprazolam is indicated for the treatment of generalized anxiety disorder and panic disorder with or without agoraphobia in adults. The FDA label advises that the physician should periodically reassess the usefulness of the drug.


title: Alprazolam

text: Alprazolam is effective in the relief of moderate to severe anxiety and panic attacks. Alprazolam is not recommended in Australia for the treatment of panic disorder because of concerns regarding tolerance, dependence, and abuse. Most evidence shows that the benefits of alprazolam in treating panic disorder last only four to ten weeks. However, people with panic disorder have been treated on an open basis for up to eight months without apparent loss of benefit.


title: Alprazolam

text: Alprazolam is recommended by the World Federation of Societies of Biological Psychiatry (WFSBP) for treatment-resistant cases of panic disorder where there is no history of tolerance or dependence.


title: Alprazolam

text: Anxiety associated with depression is responsive to alprazolam. Clinical studies have shown that the effectiveness is limited to 4 months for anxiety disorders. However, the research into antidepressant properties of alprazolam is poor and has only assessed its short-term effects against depression. In one study, some long term, high-dosage users of alprazolam developed reversible depression. In the US, alprazolam is FDA-approved for the management of anxiety disorders (a condition corresponding most closely to the APA "Diagnostic and Statistical Manual" DSM-IV-TR diagnosis of generalized anxiety disorder) or the short-term relief of symptoms of anxiety. In the UK, alprazolam is recommended for the short-term treatment (2–4 weeks) of severe acute anxiety.


title: Alprazolam

text: Alprazolam may be used in combination with other medications for chemotherapy-induced nausea and vomiting.


title: Alprazolam

text: Benzodiazepines require special precaution if used in children and in alcohol- or drug-dependent individuals. Particular care should be taken in pregnant or elderly people, people with substance use disorder history (particularly alcohol dependence), and people with comorbid psychiatric disorders. The use of alprazolam should be avoided or carefully monitored by medical professionals in individuals with: myasthenia gravis, acute narrow-angle glaucoma, severe liver deficiencies (e.g., cirrhosis), severe sleep apnea, pre-existing respiratory depression, marked neuromuscular respiratory, acute pulmonary insufficiency, chronic psychosis, hypersensitivity or allergy to alprazolam or other benzodiazepines, and borderline personality disorder (where it may induce suicidality and dyscontrol).


title: Alprazolam

text: Like all central nervous system depressants, alprazolam in larger-than-normal doses can cause significant deterioration in alertness and increase drowsiness, especially in those unaccustomed to the drug's effects.


title: Alprazolam

text: Elderly individuals should be cautious in the use of alprazolam due to the possibility of increased susceptibility to side-effects, especially loss of coordination and drowsiness.


title: Alprazolam

text: In September 2020, the U.S. Food and Drug Administration (FDA) required the boxed warning be updated for all benzodiazepine medicines to describe the risks of abuse, misuse, addiction, physical dependence, and withdrawal reactions consistently across all the medicines in the class.


title: Alprazolam

text: Alprazolam is primarily metabolized via CYP3A4. Combining CYP3A4 inhibitors such as cimetidine, erythromycin, norfluoxetine, fluvoxamine, itraconazole, ketoconazole, nefazodone, propoxyphene, and ritonavir delay the hepatic clearance of alprazolam, which may result in its accumulation and increased severity of its side effects.


title: Alprazolam

text: Imipramine and desipramine have been reported to increase an average of 31% and 20% respectively by the concomitant administration of alprazolam tablets. Combined oral contraceptive pills reduce the clearance of alprazolam, which may lead to increased plasma levels of alprazolam and accumulation.


title: Alprazolam

text: Alcohol is one of the most common interactions; alcohol and alprazolam taken in combination have a synergistic effect on one another, which can cause severe sedation, behavioral changes, and intoxication. The more alcohol and alprazolam taken, the worse the interaction. Combination of alprazolam with the herb kava can result in the development of a semi-comatose state. Plants in the genus "Hypericum" (including St. John's wort) conversely can lower the plasma levels of alprazolam and reduce its therapeutic effect.


title: Alprazolam

text: Benzodiazepines cross the placenta, enter the fetus, and are also excreted in breast milk. Chronic administration of diazepam, another benzodiazepine, to nursing mothers has been reported to cause their infants to become lethargic and to lose weight.


title: Alprazolam

text: The use of alprazolam during pregnancy is associated with congenital abnormalities, and use in the last trimester may cause fetal drug dependence and withdrawal symptoms in the post-natal period as well as neonatal flaccidity and respiratory problems. However, in long-term users of benzodiazepines, abrupt discontinuation due to concerns of teratogenesis has a high risk of causing extreme withdrawal symptoms and a severe rebound effect of the underlying mental health disorder. Spontaneous abortions may also result from abrupt withdrawal of psychotropic medications, including benzodiazepines.


title: Alprazolam

text: Overdoses of alprazolam can be mild to severe depending on the quantity ingested and if other drugs are taken in combination.


title: Alprazolam

text: Alprazolam overdoses cause excess central nervous system (CNS) depression and may include one or more of the following symptoms:


title: Alprazolam

text: The potential for misuse among those taking it for medical reasons is controversial, with some expert reviews stating that the risk is low and similar to that of other benzodiazepine drugs. Others state that there is a substantial risk of misuse and dependence in both patients and non-medical users and that the short half-life and rapid onset of action may increase the risk of misuse. Compared to the large number of prescriptions, relatively few individuals increase their dose on their own initiative or engage in drug-seeking behavior.


title: Alprazolam

text: Alprazolam, like other benzodiazepines, binds to specific sites on the GABA (gamma-aminobutyric acid) receptor. When bound to these sites, which are referred to as benzodiazepine receptors, it modulates the effect of GABA receptors and, thus, of GABAergic neurons. Long-term use causes adaptive changes in the benzodiazepine receptors, making them less sensitive to stimulation and thus making the drugs less potent.


title: Alprazolam

text: Withdrawal and rebound symptoms commonly occur and necessitate a gradual reduction in dosage to minimize withdrawal effects when discontinuing.


title: Alprazolam

text: Not all withdrawal effects are evidence of true dependence or withdrawal. Recurrence of symptoms such as anxiety may simply indicate that the drug was having its expected anti-anxiety effect and that, in the absence of the drug, the symptom has returned to pretreatment levels. If the symptoms are more severe or frequent, the person may be experiencing a rebound effect due to the removal of the drug. Either of these can occur without the person actually being drug dependent.


title: Alprazolam

text: Alprazolam and other benzodiazepines may also cause the development of physical dependence, tolerance, and benzodiazepine withdrawal symptoms during rapid dose reduction or cessation of therapy after long-term treatment. There is a higher chance of withdrawal reactions if the drug is administered in a higher dosage than recommended, or if a person stops taking the medication altogether without slowly allowing the body to adjust to a lower-dosage regimen.


title: Alprazolam

text: In 1992, Romach and colleagues reported that dose escalation is not a characteristic of long-term alprazolam users and that the majority of long-term alprazolam users change their initial pattern of regular use to one of symptom control only when required.


title: Alprazolam

text: Some common symptoms of alprazolam discontinuation include malaise, weakness, insomnia, tachycardia, lightheadedness, and dizziness.


title: Alprazolam

text: Those taking more than 4 mg per day have an increased potential for dependence. This medication may cause withdrawal symptoms upon abrupt withdrawal or rapid tapering, which in some cases have been known to cause seizures, as well as marked delirium similar to that produced by the anticholinergic tropane alkaloids of Datura (scopolamine and atropine). The discontinuation of this medication may also cause a reaction called "rebound anxiety".


title: Alprazolam

text: In a 1983 study, only 5% of patients who had abruptly stopped taking long-acting benzodiazepines after less than 8 months demonstrated withdrawal symptoms, but 43% of those who had been taking them for more than 8 months did. With alprazolam – a short-acting benzodiazepine – taken for 8 weeks, 65% of patients experienced significant rebound anxiety. To some degree, these older benzodiazepines are self-tapering.


title: Alprazolam

text: The benzodiazepines diazepam and oxazepam have been found to produce fewer withdrawal reactions than alprazolam, temazepam, or lorazepam. Factors that determine the risk of psychological dependence or physical dependence and the severity of the benzodiazepine withdrawal symptoms during dose reduction of alprazolam include: dosage used, length of use, frequency of dosing, personality characteristics of the individual, previous use of cross-dependent/cross-tolerant drugs (alcohol or other sedative-hypnotic drugs), current use of cross-dependent/-tolerant drugs, use of other short-acting, high-potency benzodiazepines, and method of discontinuation.


title: Alprazolam

text: Alprazolam is a positive allosteric modulator of the gamma-aminobutyric acid (GABA) type A receptor. When it binds to the receptor, effects of GABA are enhanced leading to inhibition of neurons in the brain. This results in effects including reduced anxiety, muscle relaxant, antidepressant and anticonvulsant activity. The activity of alprazolam in the central nervous system is dose dependent.


title: Alprazolam

text: Alprazolam is classed as a high-potency triazolobenzodiazepine: a benzodiazepine with a triazole ring attached to its structure. As a benzodiazepine, alprazolam produces a variety of therapeutic and adverse effects by binding to the GABA benzodiazepine receptor site and modulating its function; GABA receptors are the most prolific inhibitory receptor within the brain. The GABA chemical and receptor system mediates inhibitory or calming effects of alprazolam on the nervous system. Binding of alprazolam to the GABA receptor, a chloride ion channel, enhances the effects of GABA, a neurotransmitter. When GABA binds the GABA receptor the channel opens and chloride enters the cell which makes it more resistant to depolarisation. Therefore, alprazolam has a depressant effect on synaptic transmission to reduce anxiety.


title: Alprazolam

text: The GABA receptor is made up of 5 subunits out of a possible 19, and GABA receptors made up of different combinations of subunits have different properties, different locations within the brain, and, importantly, different activities with regard to benzodiazepines. Alprazolam and other triazolobenzodiazepines such as triazolam that have a triazole ring fused to their diazepine ring appear to have antidepressant properties. This is perhaps due to the similarities shared with tricyclic antidepressants, as they have two benzene rings fused to a diazepine ring. Alprazolam causes a marked suppression of the hypothalamic–pituitary–adrenal axis. The therapeutic properties of alprazolam are similar to other benzodiazepines and include anxiolytic, anticonvulsant, muscle relaxant, hypnotic and amnesic; however, it is used mainly as an anxiolytic.


title: Alprazolam

text: Giving alprazolam, as compared to lorazepam, has been demonstrated to elicit a statistically significant increase in extracellular dopamine D1 and D2 concentrations in the striatum.


title: Alprazolam

text: Alprazolam is taken orally, and is absorbed well – 80% of alprazolam binds to proteins in the serum (the majority binding to albumin). The concentration of alprazolam peaks after one to two hours.


title: Alprazolam

text: Alprazolam is metabolized in the liver, mostly by the enzyme cytochrome P450 3A4 (CYP3A4). Two major metabolites are produced: 4-hydroxyalprazolam and α-hydroxyalprazolam, as well as an inactive benzophenone. The low concentrations and low potencies of 4-hydroxyalprazolam and α-hydroxyalprazolam indicate that they have little to no contribution to the effects of alprazolam.


title: Alprazolam

text: The metabolites, as well as some unmetabolized alprazolam, are filtered out by the kidneys and are excreted in the urine.


title: Alprazolam

text: Alprazolam is a triazole and benzodiazepine derivative substituted with a phenyl group at position 6, with a chlorine atom at position 8 and with a methyl group at position 1. It is an analogue of triazolam, the difference between them being the absence of a chlorine atom in the ortho position of the phenyl ring. It is slightly soluble in chloroform, soluble in alcohol, slightly soluble in acetone and insoluble in water. It has a melting point of .


title: Alprazolam

text: For the synthesis of alprazolam the same method can be used as for triazolam, excepting that it starts from 2-amino-5-chlorobenzophenone. However, an alternative easier synthesis starting with 2,6-dichloro-4-phenylquinoline has been suggested, in which it reacts with hydrazine giving 6-chloro-2-hydrazino-4-phenylquinoline. Boiling the mixture with triethyl orthoacetate results in cyclization with the formation of the triazole ring. The product undergoes oxidative degradation in the presence of periodate and ruthenium dioxide in acetone solution, giving 2-[4-(3'-methyl-1,2,4-triazolo)]-5-chlorobenzophenone. Oxy-methylation with formaldehyde results in a product that is treated with phosphorus tribromide, when 2-[4-(3'-methyl-5'-bromomethyl-1,2,4-triazolo)]-5-chlorobenzophenone is obtained. By substituting the bromine atom with an amino group conferred by ammonia, it forms alprazolam triazolobenzophenone, following which an intermolecular heterocyclization takes place to obtain alprazolam.


title: Alprazolam

text: Quantification of alprazolam in blood and plasma samples may be necessary to confirm a diagnosis of intoxication in hospitalized patients, or to provide evidence in the case of crimes e.g., impaired driving arrest, or to assist in a thorough forensic investigation, e.g., in a medicolegal death investigation. Blood or plasma alprazolam concentrations are usually in a range of 10–100 μg/L in persons receiving the drug therapeutically, 100–300 μg/L in those arrested for impaired driving, and 300–2,000 μg/L in victims of acute overdosage. Most of the commercial immunoassays used for the benzodiazepine class of drugs cross-react with alprazolam, but confirmation and quantitative determination are usually done by chromatographic techniques.


title: Alprazolam

text: Alprazolam regular release and orally disintegrating tablets are available as 0.25 mg, 0.5 mg, 1 mg, and 2 mg tablets, while extended release tablets are available as 0.5 mg, 1 mg, 2 mg, and 3 mg. Liquid alprazolam is available in a 1 mg/mL oral concentrate. Inactive ingredients in alprazolam tablets and solutions include microcrystalline cellulose, corn starch, docusate sodium, povidone, sodium starch glycolate, lactose monohydrate, magnesium stearate, colloidal silicon dioxide, and sodium benzoate. In addition, the 0.25 mg tablet contains D&C Yellow No. 10 and the 0.5 mg tablet contains FD&C Yellow No. 6 and D&C Yellow No. 10.


title: Alprazolam

text: Alprazolam is covered under , which was filed on 29 October 1969, granted on 19 October 1976, and expired in September 1993.


title: Alprazolam

text: There is a risk of misuse and dependence in both patients and non-medical users of alprazolam; alprazolam's high affinity binding, high potency, and rapid onset increase its abuse potential. The physical dependence and withdrawal syndrome of alprazolam also add to its addictive nature. In the small subgroup of individuals who escalate their doses there is usually a history of alcohol or other substance use disorders. Despite this, most prescribed alprazolam users do not use their medication recreationally, and the long-term use of benzodiazepines does not generally correlate with the need for dose escalation. However, based on US findings from the Treatment Episode Data Set (TEDS), an annual compilation of patient characteristics in substance abuse treatment facilities in the United States, admissions due to "primary tranquilizer" (including, but not limited to, benzodiazepine-type) drug use increased 79% from 1992 to 2002, suggesting that misuse of benzodiazepines may be on the rise. In 2011, "The New York Times" reported, "The Centers for Disease Control and Prevention last year reported an 89 percent increase in emergency room visits nationwide related to nonmedical benzodiazepine use between 2004 and 2008."


title: Alprazolam

text: Alprazolam is one of the most commonly prescribed and misused benzodiazepines in the United States. A large-scale nationwide U.S. government study conducted by SAMHSA found that, in the U.S., benzodiazepines are recreationally the most frequently used pharmaceuticals due to their widespread availability, accounting for 35% of all drug-related visits to hospital emergency and urgent care facilities. Men and women are equally likely to use benzodiazepines recreationally. The report found that alprazolam is the most common benzodiazepine for recreational use, followed by clonazepam, lorazepam, and diazepam. The number of emergency department visits due to benzodiazepines increased by 36% between 2004 and 2006.


title: Alprazolam

text: Those at a particularly high risk for misuse and dependence are people with a history of alcoholism or drug abuse and/or dependence and people with borderline personality disorder.


title: Alprazolam

text: Alprazolam, along with other benzodiazepines, is often used with other recreational drugs. These uses include aids to relieve the panic or distress of dysphoric ("bad trip") reactions to psychedelic drugs, such as LSD, and the drug-induced agitation and insomnia in the "comedown" stages of stimulant use, such as amphetamine, cocaine, and MDMA allowing sleep. Alprazolam may also be used with other depressant drugs, such as ethanol, heroin, and other opioids, in an attempt to enhance their psychological effects. Alprazolam may be used in conjunction with cannabis, with users citing a synergistic effect achieved after consuming the combination.


title: Alprazolam

text: The poly-drug use of powerful depressant drugs poses the highest level of health concerns due to a significant increase in the likelihood of experiencing an overdose, which may cause fatal respiratory depression.


title: Alprazolam

text: A 1990 study found that diazepam has a higher misuse potential relative to many other benzodiazepines and that some data suggest that alprazolam and lorazepam resemble diazepam in this respect.


title: Alprazolam

text: Anecdotally, injection of alprazolam has been reported, causing dangerous damage to blood vessels, closure of blood vessels (embolization) and decay of muscle tissue (rhabdomyolysis). Alprazolam is not very soluble in water—when crushed in water it does not fully dissolve (40 µg/ml of HO at pH 7). There are also reports of alprazolam being snorted. Due to the low weight of a dose, alprazolam, in one case, was distributed on blotter paper in a manner similar to LSD.


title: Alprazolam

text: Slang terms for alprazolam vary from place to place. Some of the more common terms are modified versions of the trade name "Xanax", such as Xannies (or Xanies) and the phonetic equivalent of Zannies; references to their drug classes, such as benzos or downers; or remark upon their shape or color (most commonly a straight, perforated tablet or an oval-shaped pill): bars, ladders, Xanbars, Xans, Z-bars, handle bars, beans, footballs, planks, poles, sticks, blues, or blue footballs.


title: Alprazolam

text: In December 2013, in anticipation of the rescheduling of alprazolam to Schedule 8 in Australia, Pfizer Australia announced they would be discontinuing the Xanax brand in Australia as it was no longer commercially viable.


title: Alprazolam

text: Internationally, alprazolam is included under the United Nations Convention on Psychotropic Substances as Schedule IV.


title: Lil Baby

text: Dominique Armani Jones (born December 3, 1994), known professionally as Lil Baby, is an American rapper, singer, and songwriter. He rose to mainstream fame in 2017 following the release of his mixtape "Perfect Timing". His debut studio album, "Harder Than Ever" (2018), spawned the "Billboard" Hot 100 top 10 single "Yes Indeed" (with Drake). In 2018, he released two more mixtapes: "Drip Harder" (with Gunna), which contained the single, "Drip Too Hard", that reached #4 on the "Billboard" Hot 100, and was later certified Diamond by the Recording Industry Association of America (RIAA); and "Street Gossip", which reached #2 on the US "Billboard" 200.


title: Lil Baby

text: His second studio album, "My Turn" (2020), reached #1 on the "Billboard" 200 and is certified triple-platinum by the RIAA. The album spawned the singles, "We Paid" (with 42 Dugg) and "The Bigger Picture", both of which reached the top 10 on the "Billboard" Hot 100. In 2021, Lil Baby and rapper Lil Durk released the collaborative album "The Voice of the Heroes", which became Lil Baby's second #1 "Billboard" 200 project. He also collaborated with Drake on the songs "Wants and Needs", and "Girls Want Girls", and with Nicki Minaj on the 2022 single "Do We Have a Problem?", all three of which peaked at #2 on the "Billboard" Hot 100 chart. His feature on the song "Hurricane" by Kanye West, alongside The Weeknd, won him the Grammy Award for Best Melodic Rap Performance.


title: Lil Baby

text: In addition to his Grammy Award, Lil Baby has received an MTV Video Music Award, and two BET Awards; and was crowned the biggest all-genre Artist of the Year at the Apple Music Awards 2020.


title: Lil Baby

text: Jones was born in Atlanta, Georgia in the Oakland City neighborhood. He was two years old when his father left the family, leaving his mother to raise him and his two sisters. He dropped out of Booker T. Washington High School in ninth grade and committed to drug dealing.


title: Lil Baby

text: In early 2012, he was charged for possession with intent to sell, among other charges; and in 2013 was charged with possession of marijuana of less than an ounce. He was arrested for the third time in as many years in 2014, on charges of possession of marijuana with intent to sell, and was incarcerated for two years.