. Bulletin of the British Museum (Natural History), Geology. 362 J. J. HOOKER (Gregory 1920: pi. 18). The apparent individual nature of this fossa in Plagiolophus contrasts with the hipparionine equids, where it is considered a generic character (Woodburne & Bernor 1980). The cranial roof is known only from a fragment interpreted as part of the left frontal (PI. 24, figs le-f; Text-fig. 49B). Its dorsal surface was flat, the supraorbital rim thin and the postorbital process thin and horizontal, in contrast to other species where it is gently domed with the supraorbital rims thick and the p
. Bulletin of the British Museum (Natural History), Geology. 362 J. J. HOOKER (Gregory 1920: pi. 18). The apparent individual nature of this fossa in Plagiolophus contrasts with the hipparionine equids, where it is considered a generic character (Woodburne & Bernor 1980). The cranial roof is known only from a fragment interpreted as part of the left frontal (PI. 24, figs le-f; Text-fig. 49B). Its dorsal surface was flat, the supraorbital rim thin and the postorbital process thin and horizontal, in contrast to other species where it is gently domed with the supraorbital rims thick and the postorbital processes strongly downturned ( Text-fig. 49A). The leading edge of the orbit appears to have extended forward to a point above the junction of M1 and M2, further forward than in other species: M2 midpoint in P. annectens and and M2 3 junction in P. cartailhaci. As for the infraorbital foramen, the orbital position is ontogenetically variable, but the specimens concerned have similarly worn teeth. The orbital floor and adjacent areas are incomplete but show the course of foramina and other structures (Text-fig. 47A). The orbital opening of the maxillary foramen and probably also the anterior postpalatine canal are as in Pachynolophus lavocati (Remy 1972: 60-62, text-fig. 9), P. livin- ierensis and Hyracotherium leporinum (Savage et al. 1965: 44, 46-47, text-fig. 20), P. annectens and The squamosal is perforated by a temporal canal, opening posteriorly at the postglenoid foramen and anteriorly at the temporal foramen (Text-fig. 48). The glenoid region differs from that of as follows: the main postglenoid process is slightly more prominent but less posteriorly expanded; and the smaller posteromedial accessory process is shorter but more sharply differentiated from the main process. Individual variation in these features is appf. Please note that these images are extracted from scanned page images that may have been digitally en
Size: 1229px × 2032px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbritishmuseumnaturalhistory, bookcentury1900, bookcoll
