Tag Archives: tyler lyson

Research in the news: Eunotosaurus has the early word on turtles

There’s a twist in the turtle timeline.

Thanks to new fossil evidence, paleontologists are able to prove that turtles share a recent common ancestor with birds and crocodiles. The discovery may settle a longstanding argument among scientists about the origins of turtles. (more…)

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Study finds turtles are closer kin to birds, crocodiles than to lizards, snakes

What are turtles, and where did they come from?

Precise answers to these questions have long eluded scientists. But new research led by Daniel Field of Yale University and the Smithsonian Institution recasts the turtle’s disputed evolutionary history, providing fresh evidence that the familiar reptiles are more closely related to birds and crocodiles than to lizards and snakes. (more…)

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How the turtle got its shell

The turtle has been in no rush to give up the secret of its shell — but after two centuries of close study, scientists are filling in the story of a structure unique in the history of life.

New research led by Tyler Lyson of Yale University and the Smithsonian Institution pushes back the origins of the turtle shell by about 40 million years, linking it to Eunotosaurus, a 260-million-year-old fossil reptile from South Africa. The work strengthens the fossil record and bolsters an existing theory about shell development while providing new details about its precise evolutionary pathway. (more…)

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Discovery Places Turtles Next to Lizards on Family Tree

Where do turtles belong on the evolutionary tree? For decades, the mystery has proven as tough to crack as the creatures’ shells. With their body armor and retractable heads, turtles are such unique creatures that scientists have found it difficult to classify the strange animals in terms of their origins and closest relatives.

“We know turtles evolved from a common ancestor along with birds, lizards and snakes about 300 million years ago, but who modern-day turtles are most closely related to is one of the biggest and most controversial questions in the field of systematics,” said Tyler Lyson, a Yale University graduate student who studies the evolutionary relationships between different animal groups. (more…)

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Using Discards, Scientists Discover Different Dinosaurs’ Stomping Grounds

By examining the type of rock in which dinosaur fossils were embedded, an often unappreciated part of the remains,

Certain dinosaur species liked to live in different habitats, separated by only a few miles. Image credit: Nicholas Longrich

scientists have determined that different species of North American dinosaurs from the Late Cretaceous period 65 million years ago occupied different environments separated by just a few miles.

Hadrosaurs or duck-billed dinosaurs, along with the small ornithopod Thescelosaurus, preferred to live along the edge of rivers, according to the research. Ceratopsians, on the other hand, which include the well-known Triceratops, preferred to be several miles inland.

The findings, which appear in the online edition of the Proceedings of the Royal Society B, give scientists a more complete picture of the distribution of different species and help explain how several large herbivores managed to coexist. (more…)

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