DESCRIPTION OF A SCYLACOSAURID THEROCEPHALIAN (GLANOSUCHUS?) SKULL FOUND BY CHARLES CAMP IN SOUTH AFRICA IN 1936

Charles Camp (1893-1975) was an American paleontologist at Berkeley, who made a trip to South Africa from 1935-1936, where he excavated fossil reptiles and synapsids from the Karoo Basin. On January 26, 1936, while in Lammerskraal on the side of a hill, Camp discovered a therocephalian skull in sandstone that he described as a “fair specimen” and “almost a duplicate of the one found at... Loc. 138” (UCMP 42395). This skull was never properly described, and multiple fossils (including seventeen fragments) from Lammerskraal have been given the same specimen number (UCMP 42581), with two embedded in plaster blocks: a skull and lower jaw in ventral view and a badly weathered skull roof. Although Camp makes no mention in his journal of multiple skulls at the same site, we can only assume that all of these fossils were found by Camp at that site on that day.

Block 1 contains the lower portion of the skull and the mandibles in ventral view with some taphonomic distortion, which is the specimen Camp referred to in his journal. Four left incisors are exposed in oblique cross-section (I2-5), and two postcanines are present, although the first and last incisors, canine, and any other postcanines are missing or obscured on the skull; however, a cross section of a large canine is visible on the right side. The pterygoid and possibly other palatal bones are preserved in ventral view. Both mandibles are present, but with no visible teeth. The left mandible contains most of the dentary (minus the coronoid process) and a portion of the angular, making it more complete than the right, which lacks the posterior end of the dentary.

Block 2 contains a skull exposed in dorsal view with most of the skull roof weathered away. Some features are visible on the rostrum including a pointed, posterior process of the premaxilla where it contacts the vomer and a depression on the left of the rostrum, which may be the septomaxillary foramen. An oblique cross-section of the roots of the left canine and possibly the sixth incisor are visible.

We agree with Camp that the block 1 specimen compares well with UCMP 42395 and with Kammerer (2023) that the block 1 specimen is a scylacosaurid and possibly Glanosuchus. Block 2, however, is more difficult to identify taxonomically. It appears to be from a large therocephalian, so it may be from the same taxon as block 1. Obtaining further details on both specimens will require removing plaster or CT scanning.