Good afternoon everyone!

Look at the detail of Andrea’s shell

Having been at the KTTC for three weeks now, I have started to make a connection with the beautiful creatures that inhabit these walls. I am fascinated with their every day habits and could honestly watch them for hours on end (especially the hatchlings- so cute!). Not having much knowledge about turtles, I have done lots of research to find out more about them. I thought I would pass along some of the information I have gained throughout my investigating. A lot of the material I found is pretty technical, so I have tried to make it as simple as possible!

How did turtles’ shells come to be?

A 2009 study conducted by the RIKEN Center for Developmental Biology in Japan found that a turtle’s upper shell develops from a rare origami-like folding process that happens inside the egg. Their shoulder blades push inside their rib cages, where the ribs are then forced to grow around them. In order to find this information out, the Center observed the development of embryos of a Chinese soft-shelled turtle, chicken and mouse in order to compare the makeup of their muscles and bones. The origami-like process only happened in the turtle, where it formed a disk-shaped thickening of the skin on their backs, creating a future shell position. The ribs then expanded into the disk, making a fan-shaped pattern and encasing the shoulder blades inside.

An overall look at a turtle’s shell makeup

This means that a turtle’s skeleton is different than any other vertebrate (animal that has a backbone). They are the only species that has their shoulder blades on the inside of their rib cage, opposed to the outside. This also means that their ribs are an integral part of their shell.


What is a turtle’s shell made of?

There are two parts to a turtle’s shell- the carapace (or top shell) and the plastron (the bottom shell). The two shells are fused together by about 50 rib and vertebrae bones in order to protect the turtle’s body and vital organs. On top of the shell are different hard scale sections called scutes. These are plates made of keratin, the same material that makes human fingernails and hair. The scutes are overlapped on bones to create a strong, stiff shell. The scutes shed off regularly, as a turtle grows, and new scutes underneath are exposed. The most unique feature of a scute is their pattern. Look closely and you can see a diverse pattern amongst turtles.

A closer look at the Carapace and Plastron

I hope you’ve learned something new, like I did! I can’t wait to continue finding out more information about turtles and sharing it with you all.

For more information on turtle shells, check out some of these interesting reads:

Shells: Anatomy and Diseases of Turtle and Tortoise Shells

How the turtle got its unique hard shell

Top Ten Facts about Turtle Shells 

Do turtles ever leave their shells?

-KTTC PR Intern Jessica Brooks