Turtle I’m Totally Lacking Part of My Day Shirt
BUYIn 2015, in a 240-million-year-old lake deposit in southern Germany, Rainer Schoch and I identified skeletal remains of an even earlier stem-turtle, Pappochelys, which is Greek for “grandfather turtle.”In life, Pappochelys would have resembled a small chubby lizard more than a turtle. Its trunk ribs are broad and extend mainly sideways from the backbone. Unlike Odontochelys, the chubby Pappochelys lacks a plastron but has an extensive layer of rib-like bones embedded in muscles of the abdomen. However, these belly “ribs” resemble the slender bony growths in modern turtle embryos that eventually fuse to each other and become the plate-like bones of the plastron. Zoologists had long hypothesized that much of the plastron of turtles evolved from the belly “ribs” in a reptilian precursor.terms of both anatomy and geological age, Pappochelys seems a perfect intermediate between Eunotosaurus and Odontochelys.Following the discovery of Odontochelys in marine rocks, some paleontologists argued that turtles originally evolved in water. This could explain the half shell protecting the underside of Odontochelys: many aquatic predators attack their prey from below. However, Eunotosaurus and Pappochelys were land-dwelling animals with their undersides close to the ground.
Turtle I’m Totally Lacking Part of My Day Shirt
PappochelysIn life, Pappochelys, meaning grandfather turtle, would have looked like a chubby lizard, but its belly ribs resemble the slender bony growths in modern turtle embryos. ( Rainer Schoch, Wikimedia Commons)In discussing the origin of broadened ribs in the turtle lineage, Tyler Lyson noted that Eunotosaurus has hands that are larger than the feet and bear large claws. The robust arm bones have large attachment points for powerful muscles. These muscles could have forcefully pulled the arms back. Together, these features indicate that Eunotosaurus was a capable digger. Its broad, partially overlapping ribs would have stabilized its trunk to assist the arms during digging. However, an inflexible trunk would have slowed the animal down while moving, making it vulnerable to predators. Further expansion of the ribs and bony outgrowths from parts of the backbone would have eventually fully encased the trunk.
