The carpus of Dimorphodon restored
Several Dimorphodon specimens are known. None of the presacral specimens have tails and vice versa. The BMNH 41212 (
R.1034)
specimen is the most complete, but in situ one carpus is beneath a foot and the other is buried in the matrix, likely beneath the skull where fingers appear in the naris.
So we look elsewhere for the carpus
The Mary Anning Dimorphodon skull , NHUK PV R 1035 (Fig. 1) is another roadkill, mixing posterior skull and hand elements together in a mishmash. An extremely precise drawing (Owen 1874) provides the details needed to reconstruct the carpus and hand of this specimen.
Figure 1. Click to enlarge. Rebuilding the carpus and hand of Dimorphodon based on the Mary Anning specimen, R 1034. Yes, thats digit 5, as expected, a vestige on the dorsal side of metacarpal 4.
To no one’s surprise, the carpus of Dimorphodon is just like that of any other basal pterosaur. Nothing big to report on here.
Unfortunately the check and cranium are not clearly visible here. Parts are broken and partially buried. In any case,there is no mandibular fenestra here, as earlier discussed,
As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.
Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.
References
Buckland W 1829. Proceedings of the Geological Society London, 1: 127
Owen R 1859. On a new genus (Dimorphodon) of pterodactyle, with remarks on the geological distribution of flying reptiles.” Rep. Br. Ass. Advmnt Sci., 28 (1858): 97–103.
Owen R 1874. Monograph of the fossil Reptilia of the Mesozoic Formations. Part I. Pterosauria. Palaeontographical Society of London, 27: 1-14
Nesbitt SJ and Hone DWE 2010. An external mandibular fenestra and other archosauriform character states in basal pterosaurs. Palaeodiversity 3: 225–233
Padian K 1983. Osteology and functional morphology of Dimorphodon macronyx (Buckland) (Pterosauria: Rhamphorhynchoidea) based on new material in the Yale Peabody Museum, Postilla, 189: 1-44.
Sangster S 2001. Anatomy, functional morphology and systematics of Dimorphodon. Strata 11: 87-88
wiki/Dimorphodon
2013-01-07 20:32:37
Source: http://pterosaurheresies.wordpress.com/2013/01/08/the-carpus-of-dimorphodon-restored-2/
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