На информационном ресурсе применяются рекомендательные технологии (информационные технологии предоставления информации на основе сбора, систематизации и анализа сведений, относящихся к предпочтениям пользователей сети "Интернет", находящихся на территории Российской Федерации)

Feedbox

12 подписчиков

Fossil teeth show how a mass extinction scrambled shark evolution

Author: Carolyn Gramling / Source: Science News

lemon shark underwater
SHARK TALE After a mass extinction event about 66 million years ago, a group of sharks called carcharhiniformes, which includes the lemon shark (shown), became more abundant in the ocean.

The extinction event that wiped out all nonbird dinosaurs about 66 million years ago also shook up shark evolution.

Fossilized shark teeth show that the extinction marked a shift in the relative fates of two groups of sharks. Apex predators called lamniformes, which include modern great white sharks, dominated the oceans before the event, which took place at the end of the Cretaceous Period. But afterward, midlevel predator sharks called carcharhiniformes came to dominate the waters — as they still do today, researchers report August 2 in Current Biology.

Paleontologist Mohamad Bazzi of Uppsala University in Sweden and colleagues examined the shapes…

Click here to read more

The post Fossil teeth show how a mass extinction scrambled shark evolution appeared first on FeedBox.

Ссылка на первоисточник

Картина дня

наверх