Kabus (Permian of Namibia)

Also known as Khabus; Hill of the Captain's House; Hügel des Hauptmannshauses; Kalahari Basin

Where: Karas, Namibia (26.3° S, 18.2° E: paleocoordinates 56.3° S, 36.6° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Whitehill Formation (Ecca Group), Artinskian (290.1 - 279.3 Ma)

• "Offenbar handelt es sich um den wie verfestigter Bänderton aussehenden dickbankigen hellen Schiefer, den Range (1912. p. 30 und 52) als besonders bei Keetmanshoop verbreitet und als Hangendstes seiner 'Eurydesma-Stufe' angibt und mit dieser zusammen der Ecca-Stufe zurechnet. [Apparently, this is the bright banked shale looking like banded claystone which Range (1912 p. 30 and 52) mentiones as to be particularly occuring at Keetmanshoop, and as the uppermost hanging-wall rock of his 'Eurydesma-Stage', and which he, along with the latter, assigns to the Ecca beds.]" (Stromer, 1914).

•The term "Eurydesma-Stufe" probably refers to interglacial beds of the upper part of the Dwyka Group of modern nomenclature, in which the bivalve Eurydesma is common (see, e.g. Césari, 2007, Gondwana Res. 11(4)). Thus, the beds in question can be no older than Upper Dwyka age. Oelofsen & Araujo (1987, S. Afr. J. Sci. 83) say that the occurrence of mesosaurs in southern Africa is exclusively restricted to the Whitehill Formation ("the White Band") of the Ecca Group. Furthermore, Rossmann & Maisch (1999) list a specimen from Kabus, which in all probability comes from the locality mentioned by Stromer (1914), and explicitly state that it is from the "Whitehill Shale Formation." Thus, the present collection is assigned to the Whitehill Fm.

•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. (see time scales of Gradstein et al. (2004) and Ogg et al. (2008)). Radiometric dating within the Whitehill Fm. of the Khabus area (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.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; gray, green shale

• There is no consensus about the true nature (lacustrine/brackish/fully marine) of the water body in which the mesosaurs lived. The environment is tentatively chosen to have been marine.
• "Es ist ein sehr fester Tonschiefer von grünlichgrauer bis hellgrauer farbe und so feingeschichtet, daß er im Querbruche wie gebändert aussieht. Er spaltet nach Schichtflächen in 1-5 cm dicke Platten und ist in eckige, selten über 1 dm große Stücke zerbrochen, deren alte Bruch- und Schichtflächen durch Eisen[oxid]überzug braun gefärbt sind. [It is a very solid shale of greenish gray to light gray colour and it is finely bedded in a way that it looks banded on transverse crack surfaces. It cleaves along bedding planes into 1-5 cm thick slabs and is broken into angular pieces which are rarely larger than 1 dm, and whose older crack surfaces are brown due to a cover of iron [oxide]]." (Stromer, 1914).

Size class: macrofossils

Preservation: mold/impression

Collected by Brentano-Bernarda; reposited in the BSP

Collection methods: surface (float), acetic

• "Major Brentano sammelte sie teilweise an der Oberfläche, die meisten kamen aber bei Sprengungen zum Zweck von Baumpflanzungen aus 1/2-1 m Tiefe zutage. [Major Brentano in part collected them from the surface, the bulk, however, came to light through blastings for the purpose of planting trees, from a depth of 1/2 to 1 m.]" (Stromer, 1914).

•The fossils should be reposited in one of the collections in Munich. At least the specimen mentioned by Rossmann & Maisch (1999; the supposed holotype of Ditrochosaurus) is in the Bayerische Staatssammlung.

Primary reference: E. Stromer. 1914. Die ersten fossilen Reptilreste aus Deutsch-Südwestafrika und ihre geologische Bedeutung. Centralblatt für Mineralogie, Geologie und Paläontologie 1914:530-541 [J. Mueller/T. Liebrecht/T. Liebrecht]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 90755: authorized by Johannes Mueller, entered by Torsten Liebrecht on 15.08.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

• "Da ich also ganze Skelette und Schädel nicht habe, kann ich eine genaue Bestimmung kaum ausführen. Jedenfalls ist kein Anhaltspunkt gegeben, daß es sich um andere Reste als von Mesosauridae handelt. Weil von deren zwei Genera nur Mesosaurus in Südafrika vorkommt, überdies nichts für die große Rumpfwirbelzahl von Stereosternum spricht, wird es sich wohl nur um Angehörige jener Gattung handeln. [Since I do not have complete skeletons or skulls, I can hardly make a precise determination. There is no evidence anyways that there are remains of other than Mesosauridae. Since of the two genera of the latter only Mesosaurus is present in southern Africa, and, furthermore, nothing points towards the high number of trunk vertebrae of Stereosternum, the remains only may represent the former genus.]" (Stromer, 1914).

•Stromer (1914) briefly describes two specimens represented by limbs but states that there is a total of 36 specimens two of which were not collected on the hill of the Hauptmannshaus.

Show authors, comments, and common names
Osteichthyes
 Sauropsida - Mesosauridae
Mesosaurus sp., Mesosaurus tenuidens
Mesosaurus sp. Gervais 1865 amniote
Mesosaurus tenuidens Gervais 1865 amniote
BSP 1914 I 504 (listed as the holotype of Ditrochosaurus capensis in the paper but see Karl et al., 2007, Clausthaler Geowiss. 6); specimen probably belongs to the 34 specimens reported by Stromer (1914)