какие животные жили в эпоху динозавров
Какие животные жили на нашей планете во времена динозавров?
Как пишет издание Sciencemag, более чем 150 миллионов лет назад появились хорошо известные сегодня австралийская ехидна и утконос. Они ...
Science
Но если суша, небо и моря находились во власти динозавров, где, а главное когда обитали млекопитающие? Согласно результатам исследования, опубликованного в журнале <anchor>Science</anchor>, первые млекопитающие бегали по поверхности нашей планеты вместе с динозаврами. Как полагают исследователи, после того, как ужасные ящеры вымерли, все остальные животные вышли из тени.
When dinosaurs went extinct, many animals literally came out of the dark | Science | AAAS
Advertisement

Quick Search anywhere

Enter Search Term

Quick Search in Journals

Enter Search Term

Quick Search in Journals

Enter Search Term

Quick Search in Journals

Enter Search Term

Quick Search in Journals

Enter Search Term

Quick Search in Journals

Enter Search Term

Quick Search in Journals

Enter Search Term

Searching:

Anywhere

###### Trending Terms:

- cancer
- climate
- [artificial intelligence](/action/doSearch?AllField=artificial intelligence)
- postdoc
- aging

Quick Search anywhere

Enter Search Term

AAAS Logo

Home News All News ​When dinosaurs went extinct, many animals literally came out of the dark

# ​When dinosaurs went extinct, many animals literally came out of the dark

## Creatures from primates to the ancestors of camels began operating in the daylight about 65 million years ago

illustration of an early mammalMammals that lived at the same time as dinosaurs, such as this Kayentatherium, were most likely active at night. Mark Witton

Share:

- Facebook
- Share on X
- Linked In
- Reddit
- Wechat
- Whatsapp
- Email

The demise of dinosaurs was good news for mammals, whose numbers exploded in the aftermath. Now, a new study suggests that the behavior of mammals changed rapidly as well, as the first of our furry ancestors began venturing out in the daylight after living a primarily nocturnal existence. The switch may have even sparked the eventual evolution of our own humankind.

Paleontologists and evolutionary biologists have long thought that the original mammals were nocturnal, in part because mammals alive today still carry traits of their night-loving ancestors. Most mammals have eyes that function well in low light, for example. They also have highly developed senses of smell and hearing, and sensitive whiskers that allow them to feel what is in front of their faces—all traits that are useful in the dark.

Exactly when mammals started to venture out during the day has been a mystery, because behavior is hard to discern from fossils. Scientists rely on the shape of eye sockets and nasal cavities to infer which senses were important to an extinct animal, but those clues can be misleading.

Evolutionary biologists Roi Maor of Tel Aviv University in Israel, Kate Jones of University College London, and their colleagues decided to approach the question from a different direction. They noted the day or night preferences of more than 2415 species of living mammals and then used genetic data to draw their family trees, noting when the earliest day-active ancestors might have emerged.

The first ancestral mammal species to be active in the daytime probably lived around 65.8 million years ago—just 200,000 years after the mass extinction that wiped out all dinosaurs except birds, the team reports today in Nature Ecology and Evolution. The common ancestor of today's camels, hippos, and deer, for example, probably started foraging in daylight around that time, Maor says. Today's camels are active in the daytime, while hippos are active at night, and deer are mixed, he notes. "The daytime activity starts just as dinosaurs disappear," Maor says. Until then, he says, it was likely too risky to venture out among the sharp-eyed—and sharp-toothed—dinosaurs. The analysis suggests the expansion into daylight happened fairly quickly after the competition died out, he says. "In evolutionary terms, 200,000 years is the blink of an eye."

That's consistent with the fossil record, which shows clearly that the numbers and types of mammals expanded rapidly after dinosaurs fell by the wayside. But the glimpse into the evolution of behavior is intriguing, says evolutionary biologist Lars Schmitz of Claremont McKenna, Pitzer, and Scripps colleges in Claremont, California. The work supports the idea that mammals conquered more than territory, he says. "They also expanded their behavioral repertoire quite substantially."

And although the idea of mammals taking over spaces left empty by the dinosaurs' demise isn't new, having statistics to back up such a hypothesis "is absolutely necessary for the advancement of the field," says Luca Santini, who studies mammal ecology at Radboud University in Nijmegen, the Netherlands.

Schmitz notes that one limitation of using data from living species is that lineages that died out can also give important clues to evolution's history. "It would be awesome if one could add fossil information into this analysis," he says. That could give an even clearer picture of when and how daytime habits emerged. "It would take a lot of effort from a lot of people," he says, "but I think it's doable."

Today's primates are mostly active during the day, Maor notes, and primate ancestors seem to have been some of the first to acquire daytime habits, according to the analysis. That head start may be why we and other apes have better color vision—and duller senses of smell and hearing—than many other mammals. Primates likely had several million years longer to evolve traits that help us be successful in the sunlight, he says.

doi: 10.1126/science.aar4201

#### Relevant tags:

## About the author

Gretchen Vogel

#### Gretchen Vogel

##### Author

Gretchen Vogel is a contributing correspondent for Science magazine based in Berlin, Germany.

## More from news

13 Sep 2024

By

- Hannah Richter

13 Sep 2024

By

- Jeffrey Mervis

13 Sep 2024

By

- Myriam Vidal Valero

Got a tip for Science's news department?
Connect

### Sign up for ScienceAdviser

Subscribe to ScienceAdviser to get the latest news, commentary, and research, free to your inbox daily.

#### Advertisement

## ScienceInsider

13 Sep 2024By

- Jeffrey Mervis

13 Sep 2024By

- Myriam Vidal Valero

12 Sep 2024By

- Sean Cummings

12 Sep 2024By

- Cathleen O’Grady

#### Advertisement

## Sifter

10 Sep. 2024By

- Christie Wilcox

30 Aug. 2024By

- Christie Wilcox



29 Aug. 2024By

- Phie Jacobs



28 Aug. 2024By

- Phie Jacobs

## RecommendedClose

10 Jul 2017By

- Carolyn Gramling

Research NewsMarch 1998

Research NewsMay 1998

News FocusNovember 2004

#### Advertisement

#### SIGN UP FOR OUR CAREERS NEWSLETTER

Get great career content biweekly!

×

#### $50

#### $75

#### $100

#### Other

$

Please enter a valid amount

Single

Monthly

Email:

Please enter a valid email

Country:Country *AfghanistanAland IslandsAlbaniaAlgeriaAndorraAngolaAnguillaAntarcticaAntigua and BarbudaArgentinaArmeniaArubaAustraliaAustriaAzerbaijanBahamasBahrainBangladeshBarbadosBelarusBelgiumBelizeBeninBermudaBhutanBolivia, Plurinational State ofBonaire, Sint Eustatius and SabaBosnia and HerzegovinaBotswanaBouvet IslandBrazilBritish Indian Ocean TerritoryBrunei DarussalamBulgariaBurkina FasoBurundiCambodiaCameroonCanadaCape VerdeCayman IslandsCentral African RepublicChadChileChinaChristmas IslandCocos (Keeling) IslandsColombiaComorosCongoCongo, The Democratic Republic of theCook IslandsCosta RicaCote D'IvoireCroatiaCubaCuraçaoCyprusCzech RepublicDenmarkDjiboutiDominicaDominican RepublicEcuadorEgyptEl SalvadorEquatorial GuineaEritreaEstoniaEthiopiaFalkland Islands (Malvinas)Faroe IslandsFijiFinlandFranceFrench GuianaFrench PolynesiaFrench Southern TerritoriesGabonGambiaGeorgiaGermanyGhanaGibraltarGreeceGreenlandGrenadaGuadeloupeGuatemalaGuernseyGuineaGuinea-BissauGuyanaHaitiHeard Island and Mcdonald IslandsHoly See (Vatican City State)HondurasHong KongHungaryIcelandIndiaIndonesiaIran, Islamic Republic ofIraqIrelandIsle of ManIsraelItalyJamaicaJapanJerseyJordanKazakhstanKenyaKiribatiKorea, Democratic People's Republic ofKorea, Republic ofKuwaitKyrgyzstanLao People's Democratic RepublicLatviaLebanonLesothoLiberiaLibyan Arab JamahiriyaLiechtensteinLithuaniaLuxembourgMacaoMacedonia, The Former Yugoslav Republic ofMadagascarMalawiMalaysiaMaldivesMaliMaltaMartiniqueMauritaniaMauritiusMayotteMexicoMoldova, Republic ofMonacoMongoliaMontenegroMontserratMoroccoMozambiqueMyanmarNamibiaNauruNepalNetherlandsNew CaledoniaNew ZealandNicaraguaNigerNigeriaNiueNorfolk IslandNorwayOmanPakistanPalestinianPanamaPapua New GuineaParaguayPeruPhilippinesPitcairnPolandPortugalQatarReunionRomaniaRussian FederationRWANDASaint BarthélemySaint Helena, Ascension and Tristan da CunhaSaint Kitts and NevisSaint LuciaSaint Martin (French part)Saint Pierre and MiquelonSaint Vincent and the GrenadinesSamoaSan MarinoSao Tome and PrincipeSaudi ArabiaSenegalSerbiaSeychellesSierra LeoneSingaporeSint Maarten (Dutch part)SlovakiaSloveniaSolomon IslandsSomaliaSouth AfricaSouth Georgia and the South Sandwich IslandsSouth SudanSpainSri LankaSudanSurinameSvalbard and Jan MayenSwazilandSwedenSwitzerlandSyrian Arab RepublicTaiwanTajikistanTanzania, United Republic ofThailandTimor-LesteTogoTokelauTongaTrinidad and TobagoTunisiaTurkeyTurkmenistanTurks and Caicos IslandsTuvaluUgandaUkraineUnited Arab EmiratesUnited KingdomUnited StatesUruguayUzbekistanVanuatuVenezuela, Bolivarian Republic ofVietnamVirgin Islands, BritishWallis and FutunaWestern SaharaYemenZambiaZimbabwe

I
also wish to receive emails from AAAS/Science and Science advertisers,
including information on products, services and special offers which may
include but are not limited to news, careers information & upcoming
events.

Donate now

##### Support nonprofit science journalism

Sophisticated, trustworthy reporting about science has never been more important. As part of the AAAS mission, Science has built a global award-winning network of reporters and editors that independently cover the most important developments in research and policy.

Your tax-deductible contribution plays a critical role in sustaining this effort.

Loading...

###### Follow Us

###### Follow Us

© 2024 American Association for the Advancement of Science. All rights reserved. AAAS is a partner of HINARI, AGORA, OARE, CHORUS, CLOCKSS, CrossRef and COUNTER.

back to top

news-white-logo×

Get the latest news, commentary, and research, free to your inbox daily.