Proganochelys

Proganochelys Temporal range: Late Triassic, 210 Ma PreЄ Є O S D C P T J K Pg N ↓

Skeleton of Proganochelys quenstedti, American Museum of Natural History
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Testudinata
Genus:	†Proganochelys
Binomial name
*Proganochelys quenstedti* Baur, 1887

Proganochelys quenstedti is the oldest stem-turtle species with a complete shell discovered to date, known only from fossils found in Germany and Thailand in strata from the late Triassic, dating to approximately 210 million years ago. It has several synonyms, including Chelytherium ("Turtle Beast"), Psammochelys ("Sand Turtle"), Stegochelys ("Roof Turtle") and Triassochelys ("Triassic Turtle").

Palaeobiology

Restoration

Type specimen

In life it was about 1 meter long. Its overall appearance resembled modern turtles in many respects: it lacked teeth, likely had a beak, and had the characteristic heavily armored shell formed from bony plates and ribs which fused together into a solid cage around the internal organs. The plates comprising the carapace and plastron were already in the modern form, although there were additional plates along the margins of the shell, that would have served to protect the legs. Also unlike any modern species of turtle, its long tail had spikes and terminated in a club, its head could not be retracted under the shell, and its neck was protected by small spines. While it had no teeth in its jaws, it did have small denticles on the palate.^[1]

References

↑ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. pp. 66–67. ISBN 1-84028-152-9.

External links

Extinct turtles

Triassic period	Pappochelys Odontochelys Proganochelys

Jurassic period	Australochelys Basilochelys Caribemys Condorchelys Dinochelys Dorsetochelys Eileanchelys Eurysternum Hispaniachelys Kayentachelys Palaeomedusa Sinaspideretes Thalassemys Uluops

Cretaceous period	Allopleuron Atlantochelys Angolachelys Anomalochelys Araripemys Archelon Bouliachelys Caririemys Cearachelys Chelosphargis Chupacabrachelys Compsemys Corsochelys Cratochelone Ctenochelys Desmatochelys Emarginachelys Foxemys Gigantatypus Gilmoremys Glyptops Jiangxichelys Kallokibotion Kinkonychelys Kirgizemys Khunnuchelys Kurmademys Liaochelys Lomalatachelys Notochelone Ocepechelon Pappigerus Paracryptodira Patagoniaemys Polysternon Pleurosternon Prochelidella Protostega Protostegidae Pneumatoarthrus Sankuchemys Santanachelys Sinemys Terlinguachelys Toxochelys Trionyx kansaiensis Yaminuechelys

Paleogene and Neogene period	Acherontemys Allaeochelys Anosteira Arabemys Argillochelys Aurorachelys Baenidae Berruchelus Carbonemys Carolinochelys Cedrobaena Cerrejonemys Chelodina murrayi Chelydrops Chelydropsis Chisternon Cosmochelys Crossochelys Elseya uberrima Elseya nadibajagu Eochelone Eosphargis Euclastes Gamerabaena Glarichelys Hadrianus Hesperotestudo Hutchemys Itilochelys Kinosternon pojoaque Macrocephalochelys Manchurochelys Meiolania Meiolaniidae Megalochelys Mesodermochelys Mexichelys Miocaretta Niolamia Ninjemys Pacifichelys Palaeotrionyx Palatobaena Parahydraspis Peckemys Planiplastron Plesiobaena Procolpochelys Protochelydra Protosphargis Psephophorus Puppigerus Rheodytes devisi Stupendemys Stylemys Syllomus Warkalania

Recent	Cylindraspis species: Domed Mauritius giant tortoise Domed Rodrigues giant tortoise Réunion giant tortoise Saddle-backed Mauritius giant tortoise Saddle-backed Rodrigues giant tortoise Aldabrachelys abrupta Chelonoidis nigra abingdonii (Lonesome George)

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