Proganochelys
Name:
Proganochelys
(Early shell).
Phonetic: Pro-gan-o-kel-iss.
Named By: Georg Baur - 1887.
Synonyms: Chelytherium, Psammochelys,
Stegochelys, Triassochelys.
Classification: Chordata, Reptilia,
Anapsida?, Testudines.
Species: P. quenstedti
(type), P. ruchae.
Diet: Herbivore.
Size: About 1 meter long.
Known locations: Germany - L�wenstein Formation
& Trossingen Formation, Greenland - Fleming Fjord
Formation, and Thailand - Huai Hin Lat Formation.
Time period: Norian to Rhaetian of the Triassic.
Fossil representation: Several individuals.
For
well over a hundred years Proganochelys was
regarded as the oldest
known turtle, a title the genus held until the 2008 description
of Odontochelys,
a slightly earlier genus that lived in the Carnian
stage of the Triassic.
Proganochelys
had a developed carapace and plastron, the upper and lower parts of
the shell respectively. These were formed by bony plates that had
fused to the ribs and in life the plates would have had a covering of
horn. Proganochelys was still quite primitive in
some respects, one
of the key things being that the head could not retract underneath the
shell. Therefore to provide additional protection, the neck had a
covering of spines that would have made it much more difficult for a
predator to close its mouth around the neck. The tail of
Proganochelys was quite long for a turtle, and it
too had a covering
of spines, but more interestingly the tail ended with a small club.
Fossils
of Proganochelys are most often associated with
Germany where the genus
was first discovered, though at least three specimens of a second
species named P. ruchae are known from Thailand.
Proganochelys is
also one of the few prehistoric animals to be identified as once
living in what would become Greenland.
Further reading
- Skull morphology of the oldest turtles: a preliminary description of
Proganochelys quenstedti. - Journal of Vertebrate Paleontology. 3 (1):
25–28. - E. S. Gaffney & L. J. Meeker - 1983.
- Proganochelys ruchae n. sp., ch�lonien du
Trias sup�rieur de
Tha�lande [Proganochelys ruchae n. sp.,
chelonian from the Upper
Triassic of Thailand] - F. de Broin - 1984.
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