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         Shell Shock: Triassic Reptile Was 'Grandfather' of All Turtles

   by Reuters

   It looked like an odd lizard with a bulky body and only the skeletal
   precursor of a shell, but scientists say 240 million-year-old fossils
   unearthed in a quarry in southern Germany represent the grandfather of
   all turtles.

   The scientists on Wednesday announced the discovery of the oldest-known
   turtle, a 20-centimeter (8-inch) Triassic Period reptile combining
   traits of its lizard-like ancestors with a set of emerging turtle-like
   features.

   They named it Pappochelys, meaning "grandfather turtle," owing to its
   position at the base of the turtle family tree.

   "Pappochelys indeed forms a missing link for two reasons. It is far
   older than all so far known turtles. And its anatomy is more primitive
   in many features, showing the ancestral condition of various body
   regions," said paleontologist Rainer Schoch of Germany's State Museum
   of Natural History Stuttgart.

   It is 20 million years older than the previous earliest-known turtle,
   Odontochelys from China. While Odontochelys boasted a rudimentary shell
   on its back, Pappochelys bore only the beginnings of this
   characteristic turtle trait that evolved in many steps over tens of
   millions of years.

   "The belly armor is composed of thick, rib-like bones that are
   beginning to fuse to each other in many places," said paleontologist
   Hans-Dieter Sues of the Smithsonian Institution's National Museum of
   Natural History in Washington, calling this "an important stage in the
   evolution of the turtle shell."

   Pappochelys, known from 18 fossil skeletons, had a long tail, broad
   trunk and, rather than a beak as in later turtles, a lizard-like skull
   with numerous peg-like teeth suitable for eating insects and small
   lizards. It resided alongside a freshwater lake and may have used its
   tail for swimming and legs for steering in the water. Schoch said
   Pappochelys, as a transitional creature between lizard-like ancestors
   and later turtles, provides a much clearer picture of turtle evolution.

   "Transitional creatures are the most important contribution that
   paleontology can make to the study of evolution. They are often
   unexpected and show surprising features," Schoch said.

   "They show how complicated structures like the skull or turtle shell
   formed step by step, and also give evidence on the sequence of
   evolutionary steps."

   Pappochelys lived 10 million years before the first dinosaurs, but
   plenty of danger existed. The lake's largest predator was the 5-meter
   (16-foot) amphibian Mastodonsaurus. The 6-meter (20-foot) terrestrial
   croc relative Batrachotomus prowled the land.

   The research appears in the journal Nature.
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   [1]http://www.voanews.com/content/reu-triassic-turtle-pappochelys/28363
   01.html

References

   1. http://www.voanews.com/content/reu-triassic-turtle-pappochelys/2836301.html