Protocaptorhinus pricei
From Palaeos
Protocaptorhinus pricei is a small single tooth-rowed captorhinid from the Lower Permian red beds of North Texas and Central Oklahoma.
It is the only recognized member of the genus Protocaptorhinus.
Within captorhinids it is an "intermediate" form showing basal traits in skull structure such as a large pineal foramen in relation to skull size, single tooth-rows, small denticles on the bones of the palate, or a small, slender supratemporal that is excluded from contribution to the skull table. However P. pricei is derived in having a single median embayment of the posterior margin of the skull table, a trait shared by all "higher" captorhinids, up to and including the moradisaurines. In Romeria and Protorothyris, however, this margin is embayed bilaterally, i.e. on both sides of the median suture of the skull roof. The supratemporal in P. pricei lies transversely at the posteromedial margin of the squamosal as seen in Captorhinus, whereas in Romeria and Protorothyris it projects, in dorsal view, into the posterolateral corner of the parietal.
Two partial skulls of Protocaptorhinus have been reported from Upper Permian deposits of Zimbabwe implying that this genus spread from northwestern Pangaea into the southeastern regions of the supercontinent and survived from the Early to the Late Permian. Given both the large temporal and the large spatial distance it seems, however, quite unlikely that no divergence on a generic level should have taken place between the North American and the southern African "protocaptorhinus-like" forms and thus occurrence of Protocaptorhinus in Upper Permian strata of Zimbabwe is rather questionable. The state of knowledge on the Zimbabwean captorhinid does not allow an unequivocal assignment to Protocaptorhinus or another known or new genus so far. Thus these fossils are currently considered as Captorhinidae incertae sedis. Nevertheless it is remarkable that basal "protocaptorhinus-like" forms apparently survived through to Late Permian times.
| †Protocaptorhinus pricei Clark & Carroll 1973 | |
|---|---|
| Some Facts | |
|
Family: Captorhinidae
|
|
|
Stratigraphic Range: Lower Permian: Wolfcampian |
|
References
CASE, E. C. (1902): On some vertebrate fossils from the Permian beds of Oklahoma, pp. 62-68. in A. H. VAN FLEET, Second Biennial Report, Dept. of Geol. Nat. Hist., Territory of Oklahoma
CLARK, J. and CARROLL, R.L. (1973): Romeriid Reptiles from the Lower Permian. Bull. Mus. Comp. Zool., 144(5), pp. 353-408
GAFFNEY, E.S. and MCKENNA, M.C. (1979): A Late Permian Captorhinid from Rhodesia. Amer. Mus. Novit., vol. 2688. American Museum of Natural History, New York, 15 p.
MODESTO, S. P. (1996). A basal captorhinid from the Fort Sill fissures, Lower Permian of Oklahoma. Oklah. Geol. Notes, 56, pp. 4-14.
OLSON, E.C. (1984): The Taxonomic Status and Morphology of Pleuristion brachycoelus Case; Referred to Protocaptorhinus pricei Clark and Carroll (Reptilia: Captorhinomorpha). J. Paleontol., 58(5), pp. 1282-1295
Credits
--Zidane 11:38, 25 May 2008 (PDT)
