Browsing Volume 14 1972 by Issue Date
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ItemREVISION DU GENREPROTOCYNODON BROOM 1949 ET DISCUSSION DE SA POSITION TAXONOMIQUE(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1972) Mendrez, Christiane HeleneOn revision of Protocynodon pricei Broom 1949, it is concluded that this genus is to be placed amongst the Cynodontia Procynosuchidae. This study completes that undertaken by Broom (1949); it has also enabled us to observe the tooth replacement and, after further preparation, the internal face of the endocranium basis. In preference to the term Bauriamorpha, Scaloposauria has been chosen to include: Ictidosuchidae, Scaloposauridae, Bauriidae, Ericiolacertidae, Lycideopsidae, N anictidopsidae and Silpholestidae. In addition, after comparison between Scaloposauria and Cynodontia on one hand, and between Procynosuchidae and Silphedestidae on the other hand, the author suggests that the latter family should be reviewed and placed amongst the Cynodontia, as indicated by Haughton and Brink in 1954, and Brink (1960a), rather than amongst the Bauriamorpha, as suggested by Watson and Romer in 1956. ItemSOME MEGASPORES FROM SOUTH AFRICA AND AUSTRALIA(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1972) Dijkstra, S. J.Dr. Plumstead has sent a number of samples from South Africa to us for maceration of the spores from them and for an attempt to determine the horizons from the megaspores only. Other details were not given. In addition to these samples we had some from Australia, and it became very interesting to compare the spores from S. Africa with those from Australia or other Gondwana deposits in India or Brasil. ItemA NEW SPECIES OF MACHAERODONT FROM MAKAPANSGAT(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1972) Collings, G. E.The skull and associated mandible belonging to a new species of machaerodont, Megantereon problematicus Collings is described. The specimen came from the lowermost horizon of banded and contaminated travertines at the Makapansgat Limeworks. An estimate of its relationship with other sabre tooth cats is given. ItemON CYRBASIODON BOYCEI, BROOM 1931, (CYNODONTIA PROCYNOSUCHIDAE), FROM SOUTH AFRICA(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1972) Mendrez, Christiane HeleneThe revision of the type of Cyrbasiodon boycei has led the author to conclude that the maxilla, which constitutes this type, bears fourteen teeth corresponding to a complete maxillary series: 3 precanines, 1 canine and 10 postcanines. The general pattern of the teeth and the aspect of a remnant of secondary palate agree with those of the Cynodontia Procynosuchidae. Within this family, Cyrbasiodon can be favourably compared with the genera Leavachia and Parathrinaxodon. However, because of the anterior breadth of the palatal process of the maxilla, the different number of precanines, and of a slight difference in the canine's ornamentation, it seems preferable to maintain Cyrbasiodon as a separate genus, until the variations of the other Procynosuchidae are better known. The comparison of the tooth pattern of the Procynosuchidae with that of Diarthrognathus has shown strong similarities leading to the conclusion that the tooth pattern of the former foreshadows that of the latter. ItemTHE PARAPAPIO SPECIES OF STERKFONTEIN, TRANSVAAL, SOUTH AFRICA(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1972) Freedman, L.; Stenhouse, N. S.The premolar and molar dimensions of the Parapapio specimens hitherto described from the South African lower Pleistocene deposits at Sterkfontein have been re-examined. The relatively minor sexual dimorphism in these teeth (except P3 length) was confirmed. 103 new cercopithecoid specimens from Sterkfontein were tentatively assigned to the 3 previously described Parapapio spp. from that site. The new and old samples of each species were compared and then pooled. Analysis of this new enlarged sample, and also the newly available distribution data of Parapapio from other South African deposits, both tend to support the validity of 3 Parapapio spp., P. jonesi, P. broomi and P. whitei, at Sterkfontein. ItemA REVISED CLASSIFICATION OF CYNODONTS (REPTILIA; THERAPSIDA)(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1972) Hopson, James A.; Kitching, James W.Cynodonts are very advanced mammal-like reptiles of the Permian-Triassic which are of special interest to evolutionists because they gave rise to the Class Mammalia during Middle or Late Triassic time. Cynodonts have been known from strata of Early Triassic age in South Africa for over one hundred years, and numerous specimens have been collected and described. In recent years the record of cynodonts has been extended into earlier and later time zones, not only in southern Africa but in East Africa, South America, Russia , China, and, most recently, in North America. Much of the material from outside of Africa has not yet been fully described. ItemA RE-EVALUATION OF THE SYSTEMATICS AND MORPHOLOGY OF CERTAIN ANOMODONT THERAPSIDA(1972) Keyser, A. W.The cranial morphology of a number of specimens assigned to the genera Oudenodon, Rhachiocephalus, Aulacephalodon and Pelanomodon was investigated (Keyser, 1969). It was found that the internal morphology and the general structure of the skulls show great agreement. Many of the differences between the genera can be associated with the size of the skull. The main differences between the genera lie in the specialisation of the biting mechanism and in the relative size and shape of the nasal and prefrontal bosses. It is suggested that the genera Oudenodon and Rhachio cephalus bit off their food with the sides of the horn-covered jaws while the broadnosed genera Aulacephalodon and Pelanomodon bit with the transverse anterior tips of the jaws. This difference in the morphology of the jaws is probably indicative of a fundamental dichotomy between the two groups of genera. A similar dichotomy has been suggested for Triassic dicynodonts by Cox (1965).