In order to understand the evolution of turtles, biologists are still investigating the carapacial ridge (CR) and its development in turtle embryos. What triggers the transition from pre-turtle to turtle morphology? Studies regarding the origin of turtle shells compare gene expression patterns in the CR to similar patterns in the limb buds of vertebrates with best studied developmental systems. Learn more about how biologists examine the evolution of turtles through studying the genetic and embryonic mechanisms of the CR.

Testudines have been found throughout various continents. Learn more about how the skeletal structure of testudines date back to the Eunotosaurus africanus, pappochelys and the Odontochely semitestacea. For more on the evolution of testudines, check out the Evolutionary origin of the turtle shell. Or for more detailed stages of the testudines’s evolution, click here!

After studying the Eunotosaurus africanus, scientists believe these shells aren't just to protect turtles against predators. Check out this article to learn what turtle shells were initially meant for! For more on the benefits of CR to turtles, check out Why Turtles Evolved Shells

The skeleton of turtles has been modified by an inward folding that brings the shoulders and hips under the ribs. Click here to learn more about the turtle shell’s development!

Can’t imagine how millerattas evolved into chelydra? Check out this illustrated evolution of turtle shells!