PBDB Collection

Kimberley: Artinskian, South Africa
collected 1878

List of taxa

Where & when

Geology

Taphonomy & methods

Metadata & references

Taxonomic list

Mesosauridae

	Mesosaurus pleurogaster n. sp. Seeley 1892	3 individuals
	BMNH 49971, 49972, 49973, 49974 (all are syntypes; both the latter probably represent one and the same individual)

	Mesosaurus sp. Gervais 1865	1 individual
	" [...] contained in the Albany Museum at Grahamstown"; this is the specimen incorrectly stated to come from "Burghersdorp" in the primary reference (for details see comments on taxonomic list)
see common names

Geography

Time

Stratigraphy

Geological group:	Ecca	Formation:	Whitehill
Stratigraphic resolution:	formation
Stratigraphy comments: No formational name is given by Seeley (1892). The geographic position of Kimberley suggests that the fossils come from either the Prince Albert or the Whitehill Fm. of the Ecca Group (see fig. 24 in Catuneanu et al., 2005, Afr. J. Earth Sci. 43). Also, Rossmann (2000) explicitly states that the type specimens are from the Whitehill Formation. Radiometric ages of the Collinson Fm. (overlying the Whitehill Fm.) vary between 270 and 275 Ma (Turner, 1999, J. Afr. Earth Sci. 28(1); Fildani et al., 2007 J. Sedim. Res. 77), and radiometric ages of the basal beds of the Prince Albert Fm. (underlying the Whitehill Fm.) vary between 293 and 285 Ma (Bangert et al., 1999, J. Afr. Earth Sci. 29(1)), implying an Artinskian age for the Whitehill Fm. (cf. time scales of Gradstein et al. (2004) and Ogg et al. (2008)). Radiometric dating within the Whitehill Fm. of southern Namibia (Werner, 2006, PhD thesis, http://www.opus-bayern.de/uni-wuerzburg/volltexte/2007/2175/pdf/00-Complete_thesis-STD.pdf) corroborates an assigment to the Artinskian.

Lithology and environment

Taphonomy

Modes of preservation:	mold/impression
Size of fossils:	macrofossils
Preservation of anatomical detail:	good
Articulated whole bodies:	none
Associated major elements:	many
Disassociated major elements:	some
Temporal resolution:	time-averaged

Collection methods and comments

Collection methods:	selective quarrying,survey of museum collection
Reason for describing collection:	taxonomic analysis
Museum repositories:	BMNH
Collection dates:	1878
Collection method comments: Plaster casts of BMNH 49971 and 49972 are reposited in the collections of the Museum für Naturkunde Berlin (Liebrecht & Müller, 2009). A plaster cast of one specimen of the type series (apparently not the one figured by Seeley, 1892, fig. 1 pl. 18) is reposited under SMF-R-4953 in the collections of the Senckenberg Museum, Frankfurt/Main.
Taxonomic list comments:The Mesosaurus sp. specimen is said to come "from near Burghersdorp" by Seeley (1892) without giving any further geographic details. "Burghersdorp" probably refers to the town of Burgersdorp in the Eastern Cape Province of South Africa. This town, however, is located on outcrop of terrestrial deposits of the uppermost Beaufort Group (Lower Triassic), about 100 km SE from the Ecca-Beaufort contact. Thus, it is very unlikely that the fossil described by Seeley (1892, pp. 597/598) comes from the vicinity of Burgersdorp, Eastern Cape. It may rather come from what today is the Northern Cape Province. S. Schönland (in an endnote of a paper by Broom, 1905, Rec. Albany Mus. 1(4) p. 278) notes that the "Mesosaurus in the Albany Museum" actually is not from near Burgersdorp but from Kimberley. Hence, the Mesosaurus sp. specimen is included here.

Metadata

Reference information

Primary reference:

H. G. Seeley. 1892. The Mesosauria of South Africa. Quarterly Journal of the Geological Society of London 48:586-604 [J. Mueller/T. Liebrecht]

Secondary references:

T. Liebrecht and J. Müller. 2009. Mesosaurid specimens in the collections of the Museum für Naturkunde Berlin. [J. Mueller/T. Liebrecht/T. Liebrecht]