What was unusual about the fossil turtle Odontochelys?

What happened to sea turtles in the Cretaceous period?

As the Cretaceous progressed, sea-turtle diversity exploded. The largest animal grew to a width of 4 metres and a length of 6 metres. Some flippers were lengthened by increasing the number of toe bones. Towards the end of the period, amazingly, some of the cryptodires began an evolutionary journey back to the land.

Why did turtles evolve with broad ribbed bones?

Broad-ribbed bony structures likely evolved to provide early turtles with more stability and leverage for fossorial locomotion (burrowing). As these structures evolved and the turtle’s carapace emerged in later forms, the flexibility of the spine was reduced and crawling speed declined.

Did turtles arise as anapsids?

A third hypothesis suggests that turtles arose as anapsids—a lineage whose skull contained no openings (temporal fenestrae) in the side of the head.

How are turtles related to dinosaurs?

The DNA hypothesis suggests that turtles were a sister group to the archosaurs (the group that contains the dinosaurs and their relatives, including crocodiles and their ancestors and modern birds and their ancestors). A second hypothesis posits that turtles were more closely related to lizards and tuataras.

What happened to the dinosaurs during the Cretaceous period?

Flowering plants took root, and forests of conifers emerged. As this change began occurring, dinosaurs started sharing the world with more diverse species. In fact, many animals that aren’t dinosaurs thrived during the Cretaceous Period. Some are still with us, although they’ve gone through millions of years of evolutionary changes.

Did turtles evolve into shells?

In 2008, the discovery in China of a nearly 220 million years old fossil of an undisputed turtle precursor, represented a major advance in our understanding of the evolution of the turtle shell. This reptile, Odontochelys, apparently lived near or in coastal waters. The fossil has broad, rather straight trunk ribs and lacks any kind of carapace.

Is a tortoise a basal reptile?

Chelonians (turtles, tortoises, and terrapins) were traditionally thought of as primitive basal reptiles because of their anapsid skull (without temporal fennestra).

Are modern reptiles Anapsids or diapsids?

Modern reptiles are, for the most, diapsids, with the exception being the chelonians (turtles and tortoises), who are anapsids. Interested in learning more about anapsids, synapsids, and diapsids?

Are turtles primitive reptiles?

Believed to have been around a long time ago, turtles are among the oldest and most primitive reptiles today. Scientists claim that ancient turtles lived along with dinosaurs approximately 110 million years ago, until the K-Pg extinction event, which wiped out the dinosaurs.

What happened to dinosaurs during the Cretaceous period?

Cretaceous Period dinosaurs were many and varied. But they were also doomed. A mass extinction event at the close of this period spelled the end for dinosaurs.

How long did the Cretaceous period last?

It’s divided as: Upper Cretaceous and Lower Cretaceous. It started after the Jurassic Period and lasted 79 million of years, during which 70% of the existing species and practically all dinosaurs were extinguished.

What caused the mass extinction at the end of the Cretaceous?

The probable cause for the mass extinction at the end of the cretaceous period was when an asteroid struck Earth. The animal group that was the most successful during the Mesozic Era was the reptiles.

Why did dinosaurs go extinct?

The fossil record shows that for the first 175 million years of their existence, dinosaurs took on a huge variety of forms as the environment changed and new species evolved that were suited to these new conditions. Dinosaurs that failed to adapt went extinct.

What was the first turtle to have a shell?

The first known turtle to have a complete shell, with a full carapace, plastron, the whole package, was Proganochelys from roughly 210 million years ago. It had spikes on its neck and on its tail, which is cool.

What is the evolution of the turtle?

The evolution of turtles (by the way, to be strictly accurate, turtles and tortoises are not different things but the latter is a subset of the former) is fairly well-documented, and we have quite a lot of transitional fossils. Tortoises evolved from semiaquatic turtles, which evolved from lizard-like reptiles covered in scutes.

Did tortoises evolve from reptiles?

Based on body fossils, the first “proto-turtles” are believed to have existed in the late Triassic Period of the Mesozoic era, about 220 million years ago. The first tortoises did not evolve from any reptile. They were created by God the Creator of heaven and earth.

Are tortoises related to dinosaurs?

The closest relatives to the dinosaurs are actually birds and crocodiles, tortoises being around third on this list. It is kind of a mystery as to where tortoises actually came in during all this, but they are related closely to other lizards and therefore dinosaurs, meaning they are part of the reptile family.

What caused the extinction of dinosaurs?

The land mass Pangaea had broken up into Laurasia and Gondwanaland, and then, 130 million years ago, these land masses were beginning to fragment to form our modern-day continents. All this moving and shifting could very well have resulted in volcanic eruptions and earthquakes which could have killed the dinosaur population.

What was the last period of the Mesozoic?

(Show more) Cretaceous Period, in geologic time, the last of the three periods of the Mesozoic Era. The Cretaceous began 145.0 million years ago and ended 66 million years ago; it followed the Jurassic Period and was succeeded by the Paleogene Period (the first of the two periods into which the Tertiary Period was divided).

What is the Cretaceous period in geology?

The Cretaceous period is the third of the three divisions of the Mesozoic era of the geologic time scale. The period lasted 79 million years, from 144 million to 65 million years ago. The Cretaceous is named for chalk beds found in England. Cretaceous and surrounding time periods.

What happened during the Cretaceous period?

The Cretaceous Period was the last of three geologic time periods in the Mesozoic Era. The Cretaceous began approximately 145 million years ago at the end of the Jurassic Period and ended about 66 million years ago. The Cretaceous was succeeded by the Paleogene Period of the Cenozoic Era.