The calcitic layers of the eggshells of archosaurs (including crocodilians and birds) and turtles are composed of distinctive ...

Paleontologists assumed just one dinosaur egg type lay buried in Utah's Cedar Mountain Formation. Then they hit the jackpot.

Fossilized tracks from an early reptile are now the oldest known reptilian tracks, meaning the tetrapod ancestor most likely ...

Fossilized footprints of a primitive reptile found on a slab of rock from Australia could rewrite the story of how animals ...

A new study suggests two fossil trackways found in Australia were made by an early amniote, a group that today includes ...

The emergence of four-legged animals known as tetrapods was a key step in the evolution of many species today - including ... The other led to amniotes, whose eggs contain amniotic membranes ...

The emergence of four-legged animals known as tetrapods was a key step in the evolution of many species today ... The other led to amniotes, whose eggs contain amniotic membranes protecting the ...

Fossilized claw tracks discovered in Australia show that the animal group that includes reptiles, mammals and birds formed earlier than expected ...

The emergence of four-legged animals known as tetrapods was a key step in the evolution of many species today ... The other led to amniotes, whose eggs contain amniotic membranes protecting the ...

The footprints of a reptile-like creature appear to have been laid down around 356 million years ago, pushing back the ...