Pappochelys

Name: Pappochelys ‭(‬Grandfather turtle‭)‬.
Phonetic: Pap-po-kel-iss.
Named By: R.‭ ‬R.‭ ‬Schoch‭ & ‬H.‭ ‬-D.‭ ‬Sues‭ ‬-2015.
Classification: Chordata,‭ ‬Reptilia,‭ ‬Pantestudines.
Species: P.‭ ‬rosinae‭ (‬type‭)‬.
Diet: Uncertain.
Size: About‭ ‬20‭ ‬centimetres long.
Known locations: Germany‭ ‬-‭ ‬Erfurt Formation.
Time period: Ladinian of the Triassic.
Fossil representation: Almost complete individual.

       With a holotype specimen only twenty centimetres long Pappochelys seems an unassuming little creature at first glance,‭ ‬however this genus may just revolutionise our construction of the turtle evolutionary family tree.‭ ‬Ever since evolution went from being theory to accepted‭ ‬and proven fact,‭ ‬naturalists have being trying to find the exact place for everything,‭ ‬and much of this time turtles have always been placed within the anapsid group of reptiles.‭ ‬This is because most turtles that were known at the beginning of this research had no skull openings other than what they needed for their eyes and nostrils.‭
       As time progressed however,‭ ‬more and more fossil forms began to be added to the list,‭ ‬and some of these genera were observed to actually have additional skull openings similar to the diapsid reptiles‭ (‬lizards,‭ ‬snakes,‭ ‬crocodiles,‭ ‬dinosaurs,‭ ‬etc‭)‬.‭ ‬These observations caused many palaeontologists to reconsider the old anapsid lineage which was based more upon assumption.‭ ‬Furthermore,‭ ‬studies based upon molecular data suggested that turtles really were descended from diapsid reptiles as opposed to anapsids.‭ ‬However it takes time to change a long established theory,‭ ‬and for the most part turtles still superficially resembled anapsids,‭ ‬with no transitional forms to prove otherwise.‭ ‬Then in‭ ‬2015,‭ ‬Pappochelys was described.
       Scientists don’t actually like to use the term‭ ‘‬missing link‭’‬,‭ ‬they prefer to say‭ ‘‬transitional form‭’‬,‭ ‬but whatever you parlance,‭ ‬Pappochelys is the first genus that offers to form an evolutionary link between developed turtles and diapsid ancestors.‭ ‬Pappochelys represents a near perfect intermediate link between Odontochelys,‭ ‬one of the earliest confirmed turtles,‭ ‬and Eunotosaurus,‭ ‬a genus of reptile that lived during the Permian.‭ ‬Eunotosaurus does display special adaptations to its ribs which many researchers have interpreted as a precursor to the development of a turtle shell,‭ ‬though other researchers have said that it is merely a coincidence and that Eunotosaurus was actually a parareptile.‭ ‬The description of Pappochelys however places Eunotosaurus back into the frame as the ancestral form of turtles.‭ ‬Aside from denoting a diapsid lineage for turtles,‭ ‬the authors of the Pappochelys description also suggested that Pappochelys and other turtles lay within the Lepidosauromorpha,‭ ‬meaning that they are more closely related to lizards and snakes than they are crocodiles and dinosaurs.
       Pappochelys was a small creature and the holotype fossils were recovered from what appears to have been lake sediment.‭ ‬The bones of Pappochelys also show thickening which would have made them heavier and allow Pappochelys to swim more easily under the water.‭ ‬These all indicate that Pappochelys was likely semi-aquatic.

Further reading
-‭ ‬A Middle Triassic stem-turtle and the evolution of the turtle body plan.‭ ‬-‭ ‬Nature.‭ ‬-‭ ‬R.‭ ‬R.‭ ‬Schoch‭ & ‬H.‭ ‬-D.‭ ‬Sues‭ ‬-2015.



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