Saurorictus australis
From Palaeos
Saurorictus australis is a small single-tooth-rowed captorhinid from Upper Permian terrestrial deposits of the Karoo Basin, South Africa. Its fossil record comprises one single however almost complete, moderately deformed skull and a few scrappy postcranial elements. It is the only recognized species of the genus.
Although coming from Upper Permian strata S. australis strikingly resembles the basal single-tooth-rowed captorhinids from the Lower Permian of North America. What distinguishes S. australis from those Lower Permian representatives is the presence of a foramen on the anteriormost portion of the maxillary bone. This foramen opens anterodorsally and thus seems not to be one of the supralabial foramina that commonly line the alveolar margins of maxillary or dentary. Another difference in the skull structure of S. australis to that of other basal captorhinids is the full reduction of the supratemporal bone whose position is occupied by the anterolateral portion of the parietal. Moreover its posterior margin of the skull roof is rather straight or even pointed posteriorly instead of being embayed as seen in other captorhinids.
S. australis seems to be the most derived basal captorhinid and its presence in Upper Permian deposits implies, accompanied with its placement within captorhinid phylogeny, a ghost lineage leading back to the Early Permian for this taxon. A close relationship of S. australis to another southern African captorhinid formerly referred to Protocaptorhinus seems obvious but is as yet not confirmed.
| †Saurorictus australis Modesto & Smith 2001 | |
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Family: Captorhinidae
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Stratigraphic Range: Upper Permian: Tatarian |
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*information on lithostratigraphic subdivision of Beaufort Group from Catuneanu et al. (2005)
References
CATUNEANU, O., WOPFNER, H., ERIKSSON, P.G., CAIRNCROSS, B., RUBIDGE, B.S., SMITH, R.M.H. and HANCOX, P.J. (2005): The Karoo basins of south-central Africa. J. Afr. Earth Sci., 43(1-3), pp. 211-253
MODESTO, S.P. and SMITH, R.H.M. (2001): A new Late Permian captorhinid reptile: a first record from the South African Karoo. J. Vert. Paleont., 21(3), pp. 405-409
Credits
--Zidane 17:50, 25 May 2008 (PDT)
