Further evidence of Endothiodon bathystoma.

  • Seeley, H. G. (Harry Govier), 1839-1909.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Further evidence of Endothiodon bathystoma. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    On Further Evidence of Endothiodon bathystoma (Owen) from Oude Kloof in the Nieuwveldt Mountains, Cape Colony. By H. G. Seeley, Esq., F.R.S., F.G.S., Professor of Geography and Lecturer on Geology in King’s College, London. I am indebted to Mr. Thomas Bain, Geologist and Irrigation Officer to the Government of Cape Colony, for two bones collected by him in the Oude Kloof, a picturesque mountain-valley which traverses the Nieuwveldt range north of Tamboer, on the road towards Fraserburg. The remains consist of the left ramus of the mandible, which is almost complete, and what I regard as tho left squamosal bone under- lapped by tho malar in front, but fractured at both ends, so that only the external zygomatic bar is preserved. Small as the cranial frag- ment is, it is important as showing that the back of the head pro- bably conformed to the type of skull seen in some of the Dicyno- donts. The skull was as large as that of Dicynodon leoniceps. The Zygomatic Bar. The longitudinal squamosal bar is 20 centim. long, compressed from side to side and flattened, with the superior border convex in length. The convexity is most marked in the hinder part, where the edge of the bone is about 0‘75 centim. thick and rounded, and the depth of the bone in front of its hinder termination is 6’25 centim. A wide shallow concavity extends along the external surface, and appears to bo defined interiorly by a rugose condition of the bone. Anteriorly the depth of the bar is a little less, but its thickness augments; this is due to the strong malar bone, 2*5 centim. thick, which forms its infero-anterior border, and ex- tends behind the thin, external, zygomatic prolongation forward of the squamosal. The inferior margin of the bar appears to be concave in length to the abrupt angle where the descending bar (if it was developed) is broken away, so that the bone has a depth of only 8| centim. from the superior border. This descending bar, so characteristic of all Dicynodonts and absent from Theriodonts and the Placodontia, if present would support Sir Bichard Owen’s judgment in regarding Endothiodon as affiliated to Oudenodon} The Lower Jaw. The left ramus of the mandible, as preserved, is 30 centim. long, hut has apparently lost about 2-5 centim. from the anterior extremity. It is nearly straight, with a slight inward inflection at 1 Quart. Jouro. Geol. Soc. vol. xxxv. (1879) p. 557.