Name: Diadectes
(Penetrating bite).
Phonetic: Die-ah-deck-tees.
Named By: Edward Drinker Cope - 1878.
Synonyms: Nothodon, Empecocles,
Helodectes,
Empedias, Chilonyx, Bolbodon, Diadectoides, Animasaurus.
Classification: Chordata, Amphibia, Reptiliomorpha,
Diadectomorpha, Diadectidae.
Species: D. sideropelicus, D. lentus, D.
tenuitectus, D. carinatus, D. sanmiguelensis, D. absitus.
Type: Herbivore.
Size: Between 1.5 and 3 meters long.
Known locations: USA, concentration in the Texas Red
Beds.
Time period: Asselian through to the Kungurian of
the Permian.
Fossil representation: Many specimens are known
allowing for accurate reconstruction.
Diadectes
was
discovered and named twice by both Othniel Charles Marsh and Edward
Drinker Cope, the two central players of the ‘bone wars’. Marsh named
it Nothodon while five days later Cope released the
name Diadectes.
Normally under these circumstances, Nothodon would
have precedence but
in a twist, when they were synonymized in 1912 Diadectes
was given
precedence. This is against the standard practice of ICZN
(International Commission on Zoological Nomenclature) rules that state
that the first name should be used.
One
of the key points that
must be realised about Diadectes is that it
represents the earliest
known amphibian to be herbivorous. Its skeleton is particularly large
to accommodate an extended intestinal system so that it could digest
plant material. Its skull is particularly special in that it contains
peg like teeth at the front that would have been especially efficient
for stripping the leaves off ferns, it also had flat molar teeth for
grinding the plant material. The
skull also has a partial
second palate study of which suggests that this would have allowed
Diadectes to breathe while it chewed its food.
Due
to its transitional
nature with a mix of both amphibian and reptile features, the exact
classification is difficult and is potentially subject to change in the
future.
Further reading
- A new Diadectes. - The American Naturalist
12:565. - E. D. Cope -
1878.
- New or little known reptiles and amphibians from the Permian (?) of
Texas. - Bulletin of the American Museum of Natural History 28:163-181.
- E. C. Case - 1910.
- A description of the skulls of Diadectes lentus
and Animasaurus
carinatus. - American Journal of Science 33(30):339-348. - E.
C. Case
& S. W. Williston - 1912.
- Early Permian Vertebrates from the Cutler Formation of the
Placerville Area, Colorado. - United States Geological Survey
Professional Papers 503-C:C1-C46 - G. E. Lewis & P. P. Vaughn -
1965.
- Diadectes (Diadectomorpha: Diadectidae) from the
Early Permian of
Central Germany, with description of a new species. - Annals of
Carnegie Museum 67(1):53-93. D. S. Berman, S. S. Sumida & T.
Martens - 1998.