Image copyright Joan Costa Image caption The skeleton of a boy that shattered our view of Neanderthal brain development

A new study shows that Neanderthal brains developed more slowly than ours.

An analysis of a Neanderthal child's skeleton suggests that its brain was still developing at a time when the brains of modern human children are fully formed.

This is further evidence that this now extinct human was not more brutish and primitive than our species.

The research has been published in the journal Science.

Until now it had been thought that we were the only species whose brains developed relatively slowly. Unlike other apes and more primitive humans, Homo sapiens has an extended period of childhood lasting several years.

This is because it takes time and energy to develop our large brain. Previous studies of Neanderthal remains indicated that they developed more quickly than modern humans - suggesting that their brains might be less sophisticated.

But a team led by Prof Antonio Rosas of the Museum of Natural Sciences in Madrid found that if anything, Neanderthal brains may have developed more slowly than ours.

"It was a surprise," he told BBC News. "When we started the study we were expecting something similar to the previous studies."

Image copyright Paleoanthropology Group MNCN-CSIC] Image caption The remains were discovered inside the El Sidrón cave in Asturias, Spain.

Prof Rosas and his team believe they are right and the previous studies are wrong because for the first time they were able to study a relatively complete skeleton of a child at a crucial stage in their development.

It was of a boy, who was nearly seven-and-a-half years old when he died. His bones were found in the 49,000-year-old site of El Sidrón, in Spain.

The boy's remains are exceptionally well preserved and include a mix of baby and adult teeth, which enabled the team to accurately determine his age.

This brain is estimated to have been 87.5% of the size of an average adult Neanderthal brain upon death. A modern human child at the same general age would have, on average, a brain that was 95% the size of an adult's.

The researchers also found that some of the small bones forming the boy's backbone were not fused. In modern humans, these bones tend to fuse by the time children reach the age of six.

Image copyright Joan Costa Image caption The researchers were surprised to discover that Neanderthal brains develop more slowly

According to Prof Rosas, the finding reinforces the idea that Neanderthals were not that different from us.

The brutish picture of Neanderthals is an old one. In the last few years there has been growing evidence to suggest that they were a distinct human species with some small differences. Now we can say that their growth pattern is similar to ours, too.

The finding raises the intriguing possibility that the Neanderthals' slightly slower brain development meant that their brains might have been more advanced than ours. But Prof Rosas prefers a more prosaic interpretation.

"Neanderthals have a larger brain and larger body and so it is logical to think that the brain of the Neanderthal continues to grow for a little longer to allow their brains and bodies to get to their adult size," he explained.

Before this finding, scientists believed that modern humans were the slowest growing species. Now we know that Neanderthals took slightly longer, suggesting that both species inherited this growth pattern from a now extinct common ancestor.

Follow Pallab on Twitter</s>Neanderthals had larger brains than modern humans do, and a new study of a Neanderthal child's skeleton now suggests this is because their brains spent more time growing.

Modern humans are known for having unusually large brains for their size. It takes a lot of energy to develop such large brains, and previous research suggested that the high cost of modern-human brain development was a key reason why human growth in general is slow compared with that of other primates.

"If you look at earlier primates, they have much quicker development," said study co-lead author Antonio Rosas, chairman of the paleoanthropology group at Spain's National Museum of Natural Sciences, in Madrid. [In Photos: Neanderthal Burials Uncovered]

Researchers knew that Neanderthals had even larger brains than modern humans do, but it was unclear whether the Neanderthal pattern of growth was as slow as it is in modern humans or whether it was faster, as in other primates.

To learn more about Neanderthal development, scientists investigated an exceptionally well-preserved, nearly complete skeleton of a young male Neanderthal unearthed at the 49,000-year-old site of El Sidrón in Spain. A study in March found that Neanderthals at El Sidrón once dined on woolly rhinoceroses and wild sheep, and even self-medicated with painkillers and antibiotics.

To find out how old the Neanderthal was when he died, the scientists cut into the skeleton's teeth and counted the number of growth layers, much as one can estimate a tree's age by counting the number of rings in its trunk. They estimated the boy was about 7.7 years old when he died. The cause of his death was unclear, but it did not appear to be disease or trauma.

The skull of the Neanderthal was still maturing at the time of death, and his brain was only 87.5 percent the size of the average adult Neanderthal brain. "We think this Neanderthal boy's brain was still growing in volume," Rosas told Live Science. In contrast, "at about the same age, the modern human brain would have reached nearly 95 percent of its volume," he added.

These findings suggest "it took a little bit longer for the brain to grow in Neanderthals than in modern humans," Rosas said. Similarly, a number of the Neanderthal's vertebrae had not yet fused, although those same vertebrae tend to fuse in modern humans by about the ages of 4 to 6.

Still, the researchers noted that maturation of most other features of the Neanderthal boy's anatomy matched the maturation of those of a modern human of the same age. "Our main conclusion is that Neanderthals shared a common [overall] pattern of growth with modern humans, and this common pattern was possibly inherited from a common ancestor," Rosas said. "We thought our slow way of growing was very specific, very particular, very unique to our species," Rosas said. "What we realize now is that this pattern of slow growth that allows us to have this big brain and mature slowly, with all the advantages involved with that, was also shared by different human species." It remains uncertain what consequences, if any, this different rate of brain development might have had for how Neanderthals thought or behaved, the researchers added. The scientists detailed their findings in the Sept. 22 issue of the journal Science.
• Homo Naledi in Photos: Images of the Small-Brained Human Relative
• In Photos: Human Skeleton Sheds Light on First Americans</s>Until about the last decade or so, that's how many of us were accustomed to thinking about Neanderthal life.

But a lot has changed since then, not least of which is the emergence of smoking-gun DNA evidence that Neanderthals are, in fact, family.

Now a new study runs counter to earlier thinking by suggesting that Neanderthals reached maturity at about the same rate as modern humans.

"Neandertals have long been seen as the James Deans of human evolution—they grew up fast, died young, and became legends," Ann Gibbons writes in Science. "But now, a rare skeleton of a Neandertal child suggests that our closest cousins didn't all lead such fast lives—and that our own long childhoods aren't unique. The find may reveal how Neandertals, like humans, had enough energy to grow bigger brains."

A leading theory says that big brains take longer to develop, so in humans, childhood lasts longer to allow our brains time to grow. Chimpanzees, with much smaller brains than modern humans, mature much faster.

Back in 2010, NPR's Christopher Joyce reported on this "live fast, die young" hypothesis, which was bolstered by studies of Neanderthal skulls. As Chris wrote at the time: "Like the 'slow food' movement, 'slow growth' gave complex brains more time to 'cook,' so to speak, and then learn all those things a fancy brain could learn."

That hypothesis was based largely on the study of Neanderthal's teeth. Hominid teeth have telltale lines, similar to tree rings, that show their development from birth until the end of childhood.

But that single benchmark may not have been enough. Thanks to the discovery of a 49,000-year-old partial Neanderthal child's skeleton at El Sidrón cave in northwest Spain, the latest research has benefited from looking at more than just teeth.

While the teeth did help put the age at death for ancient Neanderthal child at 7.7 years, the team of scientists led by Antonio Rosas also measured the maturation of the skull, spine, elbow, hand, wrist and knee of what is believed to have been a boy. In six key places that calcify during development, the Neanderthal boy appeared to have matured at the same rate as a child his age today.

Gibbons writes: "The team noted that the child's brain had reached only about 87% of an average adult Neanderthal's brain size, whereas modern human brains reach 90% of their adult size by age 5."

In other words, Neanderthals may have matured even a little more slowly than modern humans.

Even so, it's just one skeleton that might not be representative of an average Neanderthal child, scientists caution.

"Neandertal first molars typically grow at a faster rate than modern human molars ... which makes this individual unusual," paleoanthropologist Tanya Smith of Griffith University in Nathan, Australia, who studies Neanderthal tooth development, is quoted by Gibbons as saying.

"Also, the brains and bodies of adult Neandertals vary in size, and this individual might have grown up to be a relatively small-brained Neandertal," [anthropologist Marcia] Ponce de León and [neurobiologist Christoph] Zollikofer [from the University of Zurich in Switzerland], write in an email quoted by Gibbons.</s>A skeleton of a seven-and-a-half year old boy who died 49,000 years ago has revealed new insights into Neanderthal growth.

A study of his bones suggests our extinct cousins were slow to grow up, just like modern children.

But owing to their different physiology - such as a larger brain case - Neanderthal children showed some unusual growth patterns.

For instance, Neanderthals had a slightly more extended period of brain growth than modern humans.

The child's brain was roughly 88 per cent the size of an average adult Neanderthal whereas modern humans tended to have on average 95 per cent of adult brain weight by that age.

Overall, the study suggests Neanderthals and modern human growth patterns are surprisingly similar - a discovery that adds to our understanding of human evolution.

Analysis of a well-preserved 49,00 year-old Neanderthal child skeleton suggests vertebrae had still not fused by the age of almost eight years old, while the same vertebrae in humans tends to fuse between the ages of four and six. They believe the specimen died at 7.69 years of age and analysis reveals some of the vertebrae had still not fused properly. Yet these same vertebrae tend to fuse in modern day humans around the ages of four to six. 'Prolonged brain growth is a way to distribute energy during a longer period which makes growth easier', Dr Rosas told MailOnline. The child's brain was roughly 88 per cent the size of an average adult Neanderthal whereas modern humans tended to have on average 95 per cent of adult brain weight by that age.

The well-preserved skeleton, dubbed El Sidrón J1, was found in a Spanish cave of the same name in the 1990s along with a dozen of his family members.

Researcher Antonio Rosas and colleagues from El Museo Nacional de Ciencias Naturales studied the specimen, dubbed had mix of baby and adult teeth.

This provided them with a rare opportunity to estimate the age at death by looking at small markings preserved in teeth.

They believe the boy died at 7.69 years of age and analysis reveals some of the vertebrae had still not fused properly.

Yet these same vertebrae tend to fuse in modern day humans around the ages of four to six.

'Prolonged brain growth is a way to distribute energy during a longer period which makes growth easier', Dr Rosas told MailOnline.

Dr Rosas said that researcher do not currently know if this would have meant they remained child-like for longer.

But the research suggests that the extended development of brain and spinal growth was a result of Neanderthals’ unique body form and physiology.

'The brain is an expensive organ which demands energy for growing and working.

'This is the biological strategy that higher primates - especially humans - have developed in evolution'.

The brain of El Sidrón J1 was roughly 87.5 per cent of the size of an average adult Neanderthal brain upon death, whereas modern humans tend to have on average 95 per cent of adult brain weight by that same age.

While there are some differences in terms of growth, overall, the similarities in delayed development between Neanderthals and modern humans is striking.

Humans have a fairly slow life development compared to some other primates.

Chimps, for instance, usually have their first child at 14.

But because human brains have more time to develop, they have more time for learning - and this was also the case for Neanderthals.

Research released earlier this month revealed Neanderthals survived much longer than previously thought.

Previous research suggested that the ‘Vindija Neanderthals’ living in Vindija Cave in northern Croatia lived as recently as 32,000 years ago.

But a new radiocarbon dating method has found that these remains were actually more than 8,000 years older than this initial estimate.

This means the Neanderthal group died just before the arrival of modern humans in Europe, the researchers, from the University of Oxford, claim.</s>Scientists who studied the fossilised skeleton of Neanderthal child have found that the growth of our ancient relatives were no different than that of a modern-day human child. "Discerning the differences and similarities in growth patterns between Neanderthals and modern humans helps us better define our own history. Modern humans and Neanderthals emerged from a common recent ancestor, and this is manifested in a similar overall growth rate," said Antonio Rosas, from Spanish National Research Council (CSIC).

"Applying paediatric growth assessment methods, this Neanderthal child is no different to a modern-day child," said Luis Rios a fellow researcher from CSIC. Neanderthals had a greater cranial capacity than today's humans. Neanderthal adults had an intracranial volume of 1,520 cubic centimetres, while that of modern adult man is 1,195 cubic centimetres, researchers said. The growth and development of this juvenile Neanderthal matches the typical characteristics of human ontogeny, where there is a slow anatomical growth between weaning and puberty.

In fact, the skeleton and dentition of this Neanderthal present a physiology which is similar to that of a sapiens of the same age, except for the thorax area, which corresponds to a child between five and six years, in that it is less developed. The only divergent aspect in the growth of both species is the moment of maturation of the vertebral column. In all hominids, the cartilaginous joints of the middle thoracic vertebrae and the atlas are the last to fuse, but in this Neanderthal, fusion occurred about two years later than in modern humans.

"The delay of this fusion in the vertebral column may indicate that Neanderthals had a decoupling of certain aspects in the transition from infancy to the juvenile phase," said Rosas. "Although the implications are unknown, this feature could be related to the characteristic enlarged shape of the Neanderthal torso, or slower brain growth," he said. The protagonist of this study was 7.7 years old, weighed 26 kilos and measured 111 centimetres at the time of death.

Although the genetic analyses failed to confirm the child's sex, the canine teeth and the sturdiness of the bones showed that it to be a male. The researchers establishes that the individual was right-handed and was already performing adult tasks, such as using his teeth as a third hand to handle skins and plant fibres. In addition, they know who his mother was, and that the child had a younger brother in the group. Furthermore, this child was found to have suffered from enamel hypoplasia when he was two or three years old. Hypoplasia - white spots on the teeth, especially visible in the upper incisors - occurs when the teeth have less enamel than normal, the cause usually being malnutrition or disease.

Discovered in 1994, the El Sidron cave - located in Pilona, northern Spain - has provided the best collection of Neanderthals that exists on the Iberian Peninsula. The team has recovered the remains of 13 individuals from the cave. The group consisted of seven adults three teenagers and three younger children. The research was published in the journal Science.</s>according to an analysis of a 49,000 year-old juvenile skeleton found in a cave in northwestern Spain.The analysis was conducted by a team led by palaeobiologist Antonio Rosas of the Museo Nacional de Ciencias Naturales in Madrid, and published in the journal The scientists found that the Neanderthal child, reliably established to have been 7.7 years old at death, had a brain that was about 87.7% the size of an adult. Human children have a brain 95% of adult size by the same age.The team also found that some of the child's vertebrae had not fused, while in humans the same bones are fully fused between the ages of four and six.The skeleton was recovered from the El Sidron cave system in Asturias in Spain, a hotspot for Neanderthal research that has so far produced more than 2,500 remains of seven adults and six juveniles.Researchers have recovered enough genetic evidence to establish that the group contained three distinct mitochondrial lineages and was likely an extended family. The skeleton used by Rosas and his colleagues has been dubbed "El Sidron J1" and is tentatively thought to be the child of "adult female 4".Approximately 36% of J1's skeleton has survived 49,000 years underground - enough to allow paleobiologists to make some firm and detailed observations about age and stature, but not about gender. However, the team writes that "evaluation of canine size and bone robusticity strongly suggests that it was male".The skeleton's dentition comprised a mixture of permanent and milk teeth, allowing a confident conclusion that the child was aged between seven-and-a-half and eight at the time of death.Close inspection of the skull remnants showed evidence of bone resorption - the process by which cells called osteoclasts break down bone tissue and release calcium into the bloodstream. This indicates that the brain was still growing.The authors take care to point out that although J1's brain was smaller - relative to adult scale - than an equivalently aged modern human the evidence says nothing about intelligence, either at that age or at full maturity.Neanderthals had larger cranial capacity than Homo sapiens, and different body shapes. Brain growth is a very energy intensive process, and the development pattern, the researchers conclude, might simply reflect different juvenile development trade-offs "rather than defining a fundamental difference in the overall pace of growth in this species of Homo".</s>When the skull of the child was first discovered, it raised more questions than answers. Although it was nearly 50,000 years old, unearthed deep within the Sidrón limestone caves of Asturias, Spain, it could easily be mistaken for that of a modern-day youth. The archaeologists who later examined it wanted to know: What was the story of this young Neanderthal? And how similar was he to today’s young Homo sapiens?

As the skeleton’s additional bones began coming to light one by one, the picture came into focus. “When the first remains of the juvenile skeleton started to appear,” says Luis Rios, a paleontologist at Madrid’s Museo Nacional de Ciencias Naturales and a coauthor on a just-published study in the journal Science, “we realized that it was a very interesting skeleton.”

The reason the skeleton was so compelling to researchers was twofold. First, as a child skeleton, the specimen offered a window into how Neanderthals grew and developed into adults, which researchers could then compare against modern Homo sapiens. Second, the unusually pristine condition of the jawbone and teeth made it possible to draw a precise estimate of the juvenile’s age at the time of death.

“Dental development is very important in human evolution and in primates,” said Antonio Rosas, the museum’s chair of paleoanthropology and lead author on the study, during a press conference on Wednesday. “And also in establishing the chronological age—that is, the age of the individual in years or days and months, or in an absolute time.”

Through an analysis of naturally occurring markings on the juvenile’s first left upper molar, Rosas and his coauthors concluded that the child had almost certainly died between the ages of 7.61 and 7.78 years. While DNA testing was inconclusive, canine tooth size and general bone robustness indicate that he was also male. Further findings, Rosas says, suggest that humans may not be as distinct from Neanderthals as we often tell ourselves—with two key exceptions.

It was over 23 years ago that a band of spelunkers in northern Spain chanced upon a cache of Neanderthal skeletons, 13 in all, in a part of the Sidrón cave complex now known as the Galería del Osario: the Tunnel of Bones. Comprising several adult males, several adolescent males, several adult females and several infants, the 49,000-year-old collection whetted the appetites of evolutionary scientists worldwide. By now, 2,500 distinct bones have been unearthed in the region—an incredible windfall for the international scientific community.

As more and more of the child’s skeleton was unearthed, the fullness of the skeleton became apparent to Rosas and his team. Ultimately, Rios says, “we were able to approach bone maturation besides dental maturation. The initial motivation for the work was the study of growth and maturation, but we kept adding more and more pieces, until the excavation finished and we had a very complete Neanderthal skeleton.”

The team performed a full examination of the skeleton in order to contrast the stages of growth in the Neanderthal child with the equivalent stages of growth in Homo sapiens. What they found was that the Neanderthal was nearly indistinguishable from Homo sapiens in the degree to which its bones had developed. From hands to knees, says Rosas, “the general pattern of growth is very similar to that of modern humans.”

However, his team did observe two important points of divergence—which could lend insight into how Neanderthals developed and aged. The first was in the spinal column. CT scans of the Neanderthal’s spine revealed that certain vertebrae in the boy’s backbone had not yet fused; those of a modern human child would have fused by age 5 or 6.

Second, inspection of the cranium—which houses the brain—implied that brain development in Neanderthals may have been a slightly more protracted process than in Homo sapiens. The endocranial volume of the specimen was about 87.5 percent of the average adult Neanderthal’s, the team reports. By contrast, for a modern 7-year-old human, the brain is typically 95 percent of the way to its adult size.

While the findings are intriguing, results that rely on a single specimen should be taken with a very large grain of salt, says University of Zurich paleoanthropologist Christoph Zollikofer. Comparing this Neanderthal’s brain size against the adult average for the whole of the Neanderthal species—as opposed to its own adult brain size, which we can never know since it died as a juvenile—is bound to result in shaky conclusions.

It could well be the case that this specimen “is just a normal kid with normal [Homo sapiens-like] brain growth,” Zollikofer says.

Rosas acknowledges the limitations inherent in this kind of study. “It’s a problem that pervades the fossil record, that sometimes conclusions rely on few individuals,” he says. Nevertheless, he maintains that such work is essential to the slow but steady progress of evolutionary research. In future years, he says, “we will try to incorporate other fossils, and later juvenile stages,” to help round out the picture.

For now, Rosas views this research as one more step along the path toward a fuller understanding of humanity’s rich evolutionary history. “We thought that our way of growing was unique to our species,” he says. Turns out, we Homo sapiens may be a lot closer to our past than any of us bargained for.</s>MADRID, SPAIN—Live Science reports that the paleoanthropology group at Spain’s National Museum of Natural Sciences studied the rate of Neanderthal development by analyzing the nearly complete skeleton of a young male Neanderthal discovered at the site of El Sidrón. The scientists estimated the boy’s age at 7.7 years old at the time of death, some 49,000 years ago, based upon the growth layers in his teeth. They also noted that the boy’s skull was still growing when he died. “We think this Neanderthal boy’s brain was still growing in volume,” said Antonio Rosas. The team estimated that the boy’s brain was about 87.5 percent of the size of the brain of a fully grown Neanderthal adult. In contrast, Rosas said modern humans of the same age have brains about 95 percent of the size of an adult’s brain. The team of researchers also noted that some veterbrae in modern human children have fused between the ages of four and six, but those same bones had not yet fused in the Neanderthal boy’s remains. The study suggests that, overall, Neanderthals shared a common pattern of growth with modern humans, which may have been inherited from a common ancestor. For more, go to “A Traditional Neanderthal Home.”</s>The first analysis of a Neanderthal boy's skull uncovered in Spain suggests that he grew much like a modern boy would. — PeopleImages/Istock.com pic via AFPMADRID, Sept 22 — The first analysis of a Neanderthal boy's skull uncovered in Spain suggests that he grew much like a modern boy would, in another sign that our extinct ancestors were similar to us, researchers said yesterday.

The rare discovery of a child's partial skeleton was found among the remains of seven adults and five other youths at the 49,000-year-old archeological site of El Sidron.

The 7.7-year-old boy, known as El Sidron J1 according to the report in the journal Science, is the first juvenile Neanderthal to be studied from the area.

"What we see in this Neanderthal is that the general pattern of growth is very similar to modern humans," said co-author Luis Rios, member of the Paleoanthropology Group at Museo Nacional de Ciencias Naturales, during a conference call with reporters.

He was still growing when he died, and his brain was about 87.5 per cent the size of an average adult Neanderthal brain, said the report.

A modern human boy would be expected to have a brain weight about 95 per cent of an adult's by that age, it added.

An analysis of his vertebrae showed some had not yet fused. These same bones tend to fuse in contemporary people at a younger age, between four and six.

Adam Van Arsdale, associate professor of anthropology at Wellesley College who was not involved in the study, described the differences between Neanderthals and humans in the paper as "subtle."

The study is "an important contribution to our understanding of human evolution," and "consistent with a now vast and growing body of research that demonstrates the similarities between Neandertals and living humans," he told AFP.

It also sheds new light on the history of human development. Neanderthals evolved separately — in western Eurasia — from humans who emerged from Africa, but they had plenty in common.

Neanderthals made art, practised rituals, buried their dead and interbred with modern humans before they went extinct some 35,000 years ago.

Neanderthals are known to have had much larger skulls than people do today, and possibly larger brains, although this did necessarily make them smarter.

But little is known about how Neanderthals got this way. One theory is that they grew up faster — that Neanderthal kids reached adult size more quickly than we do.

Previous studies suggesting this path have relied mainly on dental clues.

The latest study is based on a more complete specimen. The Neanderthal child's skeleton included 36 per cent of his left side, parts of his skull along with baby and adult teeth.

After studying his remains, researchers believe that instead of simply outpacing contemporary people in brain growth, Neanderthals may have grown up over a longer period of time.

"One mechanism of growing a larger brain would be expanding the period of growth," Rios told reporters.

Just how the Neanderthal child died is a mystery.

Scientists have found no evidence of disease, and described him as "sturdy," weighing 57 pounds (26 kilogrammes) and standing 3.6 feet tall (1.11 metres).

But his bones also contained marks similar to other remains at the cave, where other studies have suggested cannibalism may have been rampant.

"The bones have some marks, but we do not know the cause of death," co-author Antonio Rosas, chairman of the Paleoanthropology Group at Museo Nacional de Ciencias Naturales, told AFP.

Researchers also admitted there are limits to what can be inferred about the social aspects of Neanderthal childhood and development from the study.

"We have to be very cautious because we have studied one skeleton," said Rios.

Milford Wolpoff, professor of anthropology at the University of Michigan, agreed "that Neandertals may have had extended period of brain growth."

But he questioned the authors attempt to age the child so precisely.

"Age determination for dead people is at best an estimate, and giving an age estimate to two decimal places (they say 7.69 years of age) really overstates the accuracy that is possible," said Wolpoff, who was not involved in the study.

He also questioned the comparison to modern humans, since different rates of brain growth are common across various people and time periods.

Furthermore, assessments of Neanderthal brain size could be skewed high, because most of the specimens paleoanthropologists have belong to males, who were physically larger than females. This may lead us to believe Neanderthals were bigger on average than they actually were, he added.

Therefore, trying to derive much meaning from small skull size differences might be a fruitless endeavour, when the bigger picture is clear.

"Neanderthal brain growth may or may not be like any human population, but surely seems to fit within the normal human range," Wolpoff said. — AFP-Relaxnews</s>About 49,000 years ago a Neanderthal boy died young. The cause of death isn't clear. Scientists who pored over his bones many millennia later found no signs of fatal trauma or disease. But something cut his life abruptly short about four months shy of his eighth birthday.

He left behind a remarkably complete skeleton. The Neanderthal bones tell a story of a species that grew slowly through early childhood, a team of scientists reported in the journal Science on Thursday. That story, they say, is quite like our own.

“What we see in this Neanderthal is the general pattern of growth is very similar to that of modern humans,” said Luis Ríos, a paleoanthropologist at the National Museum of Natural History of Spain, during a news conference on Wednesday.

Katerina Harvati, an expert in Neanderthal evolution at the University of Tubingen in Germany who was not involved with the study, said that “one must be careful in extrapolating findings from one individual. Nevertheless, this specimen is very complete, making it a particularly good case study.”

Between 2000 and 2013, excavators removed more than 2,500 fossilized bones from the Spanish cave system known as El Sidron. Researchers have so far identified 13 individuals. This includes several adults, as well as the young boy and a child of about 2 or 3 years old. The bones were jumbled and must be pieced together, jigsawlike. Some of the bones have cut marks made after death, suggesting postmortem cannibalism.

Yet these Neanderthals were no knuckle-dragging carnivores. There's evidence from earlier studies that they ate nuts and fungus as part of a mostly vegetarian diet. They medicated themselves with plants that acted like natural painkillers. The sophistication of the stone tools found in El Sidron indicate these archaic humans lived during the Middle Paleolithic period, about 49,000 years ago.

About 36 percent of the juvenile Neanderthal's skeleton was still intact. El Sidron J1, which is what the researchers called him, had a complete lower jaw, 30 teeth, bits of skull, backbone, ribs, arms and a knee. He would have been about 3-foot-8 and 60 pounds. Though tests of his ancient DNA were inconclusive, the teeth size and bone shape indicated the Neanderthal was male.

Ríos and his colleagues used J1's teeth to determine the boy's age. This was “established mostly through the dental histology,” said study author Antonio Rosas, a paleoanthropologist at Spain's National Museum of Natural History. Which is to say the researchers used microscopes to track growth lines in the tooth enamel. They checked the dental age against the skeleton's maturation, particularly in the best-preserved areas: his elbow, wrist, hand and knee. The bones agreed with the dental estimate. J1 was 7.7 years old, give or take a month, when he died.

That's young, even for a Neanderthal. By one recent estimate, one in four Neanderthals lived past the age of 40, a life span on par with early humans.

J1, when compared with the development of modern kids, fell mostly within the expected human range. There were two major exceptions. Based on his cranial bones, the volume of J1's brain was about 88 percent that of the average adult Neanderthal's. He would have been underdeveloped if he were one of us. A 7-year-old modern human's brain is 95 percent of an adult's. Also, the bones in J1's spine had not yet fully fused, something that happens to human children around age 5 or 6.

The authors argue that these changes did not signal a fundamental difference in the pace of Neanderthal development. The body shape and large Neanderthal skull might have taken more energy to finish growing. But overall, they concluded, J1 reveals that Neanderthals grew up like modern human children. That is, slowly.

Humans are late bloomers compared with other primates. Chimpanzees grow much faster after birth; studies suggest they do not have an adolescent growth spurt. Our bodies pump the brakes after infancy, only to speed up again after a long pause. Biologists hypothesize this pause allows young brains to soak in socially complex environments over a period of years, rather than maxing out in size too early.

The authors acknowledged that their conclusions were limited by the fact J1 was their only specimen in this research and said they hope to add data from other juveniles. Still, Ríos said, using the best fossil evidence — in this case, one skeleton — “is the only way to move forward” in the study of archaic humans.

Harvati said this evidence will also have to be reconciled with other research, which hints at faster growth rates in Neanderthal children, at least based on their teeth. "It maybe that the differences are more subtle than initially thought," she said, "with Neanderthals falling within the range of modern human variation, albeit at the faster end of the spectrum."

Rosas said that the finding “has to be put in context of our evolution.” Our delayed adolescence was thought to be uniquely human, he said. After all, it gave us “this big brain.” But, if both species bloomed late, this trait likely appeared somewhere in our common evolutionary history, he said, on the shared path to Neanderthals and Homo sapiens.

This post has been updated.

A scientist needed help studying Neanderthal teeth — so he asked his dentist

Your Neanderthal DNA might actually be doing you some good
A new study shows that Neanderthal brains developed more slowly than those of modern humans, contradicting previous studies.