Introduction
Turtles are among the oldest creatures currently living on Earth. This is primarily due to the fact that their evolutionary journey provided them with features necessary for long-term survival.
Main body
Looking at turtles, it is impossible to miss their resemblance to lizards and other reptiles. This is mainly because reptiles were the primary predecessors of turtles. Bowen explains that the closest ancestor of sea turtles was a small reptile called Eunotosaurus Africanus. One of the most essential features of this reptile was its ribcage. In contrast with other animals, it was curved backward, and the bones in it were extremely thick. Researchers suggested that this structure helped Eunotosaurus to protect itself from predators, thus surviving and evolving over time into modern-day turtles.
However, recent developments in the field of evolutionary biology led some scientists to believe that the purpose of the ‘shell’ was different at first. According to Yong, the ribcage structure of intermediate fossils suggested that it was not used for defense against predators. On the contrary, wide and thick ribs allowed the ancestor of turtles to dig the soil more quickly and effectively (Yong). During evolution, first, the lower ribs and then the upper ribs fused together and merged with the spine (Yong). Some generations further, they started growing over the shoulder blades, creating a fully formed shell. The structure was used by Eunotosaurus as leverage during digging, as it prevented their bodies from shifting too much.
Conclusion
Over time, the shell’s added purpose became protection, thus causing it to grow stronger, bigger, and thicker. This gave rise to turtles that survived to the modern days. The evolution of turtles shows how exciting and intriguing evolutionary biology can be. Just one discovery can provide scientists with a new idea, changing their views about specific evolutionary processes and structures.
Works Cited
Bowen, Dan. “The Evolution of Turtles: Where Did Sea Turtles Come From?” Two Oceans Aquarium. 2017. Web.
Yong, Ed. “Why Turtles Evolved Shells: It Wasn’t for Protection.” The Atlantic. 2016. Web.