The discovery of the Grandfather Turtle reveals how turtles got their shell. The newly found fossil is 240 million years old and it brings valuable information to nowadays scientists.
The fossilized Pappochelys rosinae, which means Grandfather Turtle was found in Germany, at the Schumann quarry. Upon analysis, the scientists have deemed it an ancestor of nowadays turtles.
Until this fossil was discovered, the most pertinent theory regarding the nature of turtles was that they came from dinosaurs and that they are basically the their living heirs, like birds are.
However, the study based on the analysis of the Grandfather Turtle that was recently published in the prestigious scientific journal Nature, concludes that an entirely new theory might be closer to the truth.
Hans-Dieter Sues, the lead author of the study said that it is more likely that turtles are actually reptiles, “a large group of legless lizards” as he put it.
Upon close study of the fossil, it became apparent to the researchers that while the ancient turtle did not have a shell at that time, it was however in the making, since there were obvious signs pointing out to the transformation that was underway.
The fossil presented T-shaped ribs that were particularly broad and also a bony web on its abdominal wall, both clear signs of the making of a shell that eventually came many years later.
“Modern developmental studies indicate that the turtle shell formed from bony outgrowths of the vertebrae and ribs.”, said Hans-Dieter Sues.
As for the main role of the shell, the scientists have concluded that it was developed so as to protect the vital organs of the animal. Furthermore, researchers suspect that when the shell was actually produced it was for aquatic turtles and that it played a very important role in their level of buoyancy.
By developing a hard shell, the sea turtles could get much faster, much easier and much deeper in the water, because it helped them develop a significant negative buoyancy, as their bodies had become much heavier.
As for the rest of the reptile family, the German scientists explain that they did not develop shells of their own, simply because they had other needs in order to keep safe from their own predators in their own environment. For instance, snakes lost their legs and developed an entirely new type of movement and they managed to survive.
And there were some unsuccessful species out there as well, such as all the extinct lizards who did not choose the right way on the evolutionary path and did not survive along the years.
Shells however seem to have been a success, since we have a wide variety of turtles that are still here with us today. It is a pretty good defensive method to develop a thick hard shell that can fit all of the body inside if necessary and that covers the vital organs at all times.
It is not certain for now that this is the true origin or turtles, since Sues has only launched a theory that needs to be analyzed further. Paleontology experts seem to regard Sues’ theory as being a very solid one, but the need for further research remains.
As Sues points out himself, “molecular data places turtles closer to crocodylians and birds, whereas anatomical data have always favored a closer relationship between turtles, lizards, and their kin.”. So this is not the last piece of the turtle puzzle by far.
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