On Delphinognathus conocephalus (Seeley) from the Middle Karoo beds, Cape Colony, preserved in the South African Museum, Capetown / by H.G. Seeley.
- Seeley, H. G. (Harry Govier), 1839-1909.
- Date:
- 1892
Licence: Public Domain Mark
Credit: On Delphinognathus conocephalus (Seeley) from the Middle Karoo beds, Cape Colony, preserved in the South African Museum, Capetown / by H.G. Seeley. 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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![[From the Quarterly Journal of the Geological Society for August 1892, Vol. xlviii.] On Delpiiinognathus conocepiialus (Seeley) from the Middle Karoo Beds, Cape Colony, preserved in the South African Museum, Capetown. By H. G. Seeley, Esq., F.B.S., F.G.S., Professor of Geography and Lecturor on Geology in King’s College, London. The skull herein described is the only portion of the animal collected. No locality for it is recorded in the South African Museum, but Mr. Thomas Bain, the Government geologist in Cape Colony, believes it to have been collected by himself from near Beaufort West. It is slightly distorted with the folding of the strata. The preservation of the specimen leaves something to be desired, for the pre-orbital region is more or less obscured by weathering, which has destroyed the superior contour of the snout, the alveolar border, and the ante- rior extremity of the jaws. The occipital condyle and much of the occipital plate from the back of the skull are also lost. But, notwith- standing these defects, the skull is the most interesting Anomodont preserved in Cape Colony, and indicates a new family of fossil Reptilia. The head is characterized by its broad, high, vertical occipital plate. The broad subpentagonal roof to the brain- case (fig. 2) ascends laterally from the inclined temporal region, and is elevated in a cone, which terminates in a large, circular, crater-like parietal foramen. The skull has large sub-circular vertical orbits, placed far backward above the hinder extremity of the lower jaw, so as to converge forward. The temporal fossse are short and small, owing to the position of the orbits and the width of the cerebral region. The quadrato-squamosal region is directed obliquely forward, and forms a vertical articular surface to articulate with the lower jaw, which is singularly deep posteriorly, and suggests the jaw of a porpoise in its form. The skull is now 31 centim. long, but was probably somewhat longer. The occipital plate was higher than wide. It extends 24 centim. above the inferior margin of the mandible. The bones which compose the plate lie in a vertical plane, and are conditioned as in Dicynodon and its allies, but their several limits cannot be traced. The transverse measurement of the back of the head over the foramen magnum is 20 centim., and at the lateral borders the squamosal bones are prominent. Those bones make the external narrow, vertical borders of the small temporal vacuities. The vertical measurement from the base of the occipital condyle to the Summit of the occipital plate is 16 centim.; the superior lateral contours of the plate converge upward in half an ellipse. Inferi- orly, there is only a slight narrowing caused by a slight approxi- mation of the squamosal bones in the region of the condyles for the lower jaw. The foramen magnum is not clearly evidenced, but appears to have been small, narrow, and vertical, not more than 2-7](https://iiif.wellcomecollection.org/image/b22412670_0005.jp2/full/800%2C/0/default.jpg)
