|Image credit: Pixabay / markovojkic|
Like children assembling a jigsaw puzzle, evolutionists have long been trying to piece together the mysteries of turtle shell origins. And their various versions of “Why the turtle got its shell” sound like tales from Rudyard Kipling’s Just So Stories. According to Dr. Tyler Lyson, lead author of “Fossorial Origin of the Turtle Shell” published in Current Biology, “The answer seems pretty obvious”—the turtle evolved its shell “for protection.”To read the rest, click on "Why Did Turtle Shells Evolve?"
The “protection” answer is not so obvious, however, when we remember that turtle shells vary a lot, even among living turtles. A fully developed carapace with fused flat ribs protects a turtle. But a set of flattened unfused ribs—like the “incomplete” carapace of the fossil turtle Eunotosaurus—offers no apparent protection. In fact, it seems like those wide, unfused ribs would just get in the way, making it difficult to breathe and move. If such “incomplete” shells offer no protection and clear disadvantages, how could protection be the driving force for turtle shell evolution?
Believed to be the first reptile to transition toward turtlehood, Eunotosaurus has until now presented an evolutionary mystery: How could its broad, flat, unfused ribs offer any survival advantage? A new and fairly complete Eunotosaurus fossil has allowed turtle experts to solve this mystery. Their discovery has not completed the picture of turtle shell evolution, however, but instead revealed an extinct turtle variety that was exceptionally well designed for digging.