Palaeontologia africana

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ISSN (print): 0078-8554 ISSN (electronic): 2410-4418 For queries regarding content of Palaeontologia africana collections please contact Jonah Choiniere by email : jonah.choiniere@wits.ac.za or Tel : 011 717 6684

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Craniomandibular anatomy of the akidnognathid therocephalian Olivierosuchus parringtoni from the Early Triassic of South Africa
(Evolutionary Studies Institute, 2023) Gigliotti, Alessandro; Pusch, Luisa C; Kammerer, Christian F; Benoit, Julien; Fröbisch, Jörg
Therocephalians were an ecomorphologically varied and diverse-sized group of therapsids with widespread distribution during the late Permian and earliest Triassic periods. Here, we redescribe the holotype of the therocephalian Olivierosuchus parringtoni (BP/1/3849) from the Early Triassic Lystrosaurus declivis Assemblage Zone in the main Karoo Basin of South Africa. The specimen includes a complete skull, mandible, and the anterior portion of the skeleton. Previously unknown endocranial features are described using high-resolution computed tomography (CT), including internal surfaces of braincase and palatal bones, as well as soft tissue structures such as the brain and inner ear endocasts. Comparisons with closely related therapsids permit a detailed comparative analysis of the brain and inner ear morphology of Olivierosuchus.
Re-identification and updated stratigraphic context of the holotypes of the late Permian tetrapods Dicynodon ingens and Scymnosaurus warreni from KwaZulu-Natal
(Evolutionary Studies Institute, 2023) Groenewald, David P; Kammerer, Christian F
Two historical therapsid holotypes held in the collections of the KwaZulu-Natal Museum (Dicynodon ingens Broom, 1907 and Scymnosaurus warreni Broom, 1907) are redescribed. The holotype of D. ingens is a snout tip of a large dicynodontoid that can be re-identified as a specimen of Daptocephalus leoniceps based on premaxillary proportions and palatal morphology. The holotype of S. warreni consists of a dorsoventrally crushed therocephalian snout, which is here re-identified as that of Moschorhinus kitchingi based on size, general proportions, tooth count, and septomaxillary morphology. The localities of both specimens are biostratigraphically assigned to the Lystrosaurus maccaigi-Moschorhinus Subzone of the Daptocephalus Assemblage Zone (latest Permian).
Cranial morphology and phylogenetic analysis of Cynosaurus suppostus (Therapsida, Cynodontia) from the upper Permian of the Karoo Basin, South Africa
(Evolutionary Studies Institute, 2018-03) van den Brandt, Marc; Abdala, Fernando
Non-mammaliaform cynodonts are an important fossil lineage which include the ancestors of mammals and which illustrate the gradual evolution of mammalian characteristics. The earliest cynodonts (‘basal cynodonts’) are known from the late Permian. Cynosaurus suppostus is the second most abundant basal cynodont from the late Permian of the Karoo Basin of SouthAfrica, but is poorly studied, with the most recent description of this taxon being 50 years old. Since then, several important new specimens of this species have been collected, meriting a thorough description of its cranial anatomy and exploration of its interspecific variation. Here we present a comprehensive description of the cranial morphology of Cynosaurus suppostus, producing an updated diagnosis for the species and comparisons amongst basal cynodonts. Cynosaurus is identified by three autapomorphies amongst basal cynodonts: a subvertical mentum on the anterior lower jaw; a robust mandible with a relatively high horizontal ramus; and the broadest snout across the canine region, representing up to 31.74% of basal skull length. One of the new specimens described here preserves orbital scleral ossicles, structures rarely preserved in non-mammaliaform cynodonts. Cynosaurus is now only the third cynodont in which scleral ossicles have been reported.Anupdated phylogenetic analysis of basal cynodont interrelationships recovered Cynosaurus suppostus as a member of the Galesauridae in only two of 16 most parsimonious trees, providing poor support for its inclusion in that family. The majority of known Cynosaurus specimens were collected in a geographically restricted area approximately 150 kilometres in diameter. Most specimens have been recovered from the latest Permian Daptocephalus Assemblage Zone, with only two specimens known from the older Cistecephalus Assemblage Zone.
The first skeletal evidence of a dicynodont from the lower Elliot Formation of South Africa
(Evolutionary Studies Institute, 2018) Kammerer, Christian F.
Historical fossil specimens from the lower Elliot Formation are identified as representing a large-bodied dicynodont, the first known from skeletal material in the Late Triassic of South Africa. Although fragmentary, these fossils differ from all other known Triassic dicynodonts and are here described as a new taxon, Pentasaurus goggai gen. et sp. nov. Pentasaurus can be distinguished from other Triassic dicynodonts by a number of mandibular characters, most importantly the well-developed, unusually anteriorly-positioned lateral dentary shelf. Phylogenetic analysis indicates that Pentasaurus is a placeriine stahleckeriid. Placeriines include the latestsurviving dicynodonts but their remains are primarily known from the Northern Hemisphere, with their only previously-known Southern Hemisphere representative being the Middle Triassic Zambian taxon Zambiasaurus. The discovery of a placeriine in the Late Triassic of SouthAfrica supports recent proposals that local climatic conditions, not broad-scale biogeographic patterns, best explain the observed distribution of Triassic tetrapods. The tetrapod fauna of the lower Elliot Formation is highly unusual among Triassic assemblages in combining ‘relictual’ taxa like dicynodonts and gomphodont cynodonts with abundant, diverse sauropodomorph dinosaurs.
Two unrecognised burnetiamorph specimens from historic Karoo collections
(2016-03) Kammerer, Christian F.
Two historical specimens from Permian rocks of the Karoo Basin represent previously unrecognised members of the rare therapsid group Burnetiamorpha. These specimens cannot be referred to any existing burnetiamorph species, but are left in open nomenclature because of their incompleteness (both are isolated skull roofs). The first specimen is from the Tapinocephalus Assemblage Zone (AZ) and is characterized by heavily pachyostosed supraorbital bosses and a low nasal crest. The second specimen is from the Tropidostoma AZ and is generally similar to the Malawian taxon Lende, but is unique among described burnetiamorphs in having a frontoparietal ‘dome’ that surrounds the pineal foramen. Phylogenetic analysis of burnetiamorphs recovers support for a split between Proburnetia and Burnetia-like burnetiids, here named Proburnetiinae subfam. nov. and Burnetiinae Broom, 1923.
Preliminary phylogenetic analysis and stratigraphc congruence of the dicynodont anomodonts (Synapsida: Therapsida)
(Bernard Price Institute for Palaeontological Research, 2001) Angielczyk, Kenneth D
A preliminary phylogenetic analysis of 20 well-known dicynodont taxa was conducted using modern cladistic methods. Many past phylogenetic hypotheses were corroborated, but others conflict with the results of this analysis. Most notably, Diictodon, Robertia, and Pristerodon are reconstructed in more basal positions than previously suggested, whereas Endothiodon and Chelydontops occupy a more crown ward position. These findings are consistent with novel evolutionary scenarios for characters such as the presence of postcanine teeth and anterior palatal ridges. The Relative Completeness Index and Gap Excess Ratio were used to examine the degree of fit between the most parsimonious cladograms of this study and the stratigraphic record of the dicynodonts. Although the results of this analysis suggest that the preferred cladogram is relatively consistent with stratigraphy, the presence of some ghost ranges and ghost lineages imply that the fossil record of dicynodonts is not as complete as is sometimes stated. These findings are important because there is a long tradition of intensive collecting in regions where dicynodont fossils are common; sections of several dicynodont lineages may not be preserved in these areas.
A dicynodont trackway from the Cistecephalus Assemblage Zone in the Karoo, East of Graaff-Reinet, South Africa
(Bernard Price Institute for Palaeontological Research, 2002) de Klerk, William J
This paper reports a partially exposed late Permian palaeosurface with preserved vertebrate tracks at the "Asante Sana" private game reserve in the vicinity of Petersburg, 46km east of Graaff-Reinet. Excavation of the palaeosurface over an area of 34m2 revealed clear footprints and trackways of six large tetrapods that walked in a westerly direction across a semi-consolidated muddy substrate in the distal floodplain area of a large fluvial system. Clear heteropodous impressions of the footpads and individual toes and claws are preserved as concave epirelief moulds. It is concluded that these fossil tracks were made by a group of therapsids, specifically a group of large dicynodonts, possibly Aulacephalodon. The tracks are here assigned to the ichnospecies Dicynodontipus icelsi sp. nov. A continuous trackway and numerous less distinct individual prints and markings made by smaller tetrapods are also preserved on the palaeosurface. It is probable that these tracks were left by Diictodon, a small common dicynodont of the time.
A review of the reptile and amphibian assemblages from the Stormberg of southern Africa, with special emphasis on the footprints and the age of the Stormberg
(Bernard Price Institute for Palaeontological Research, 1984) Olsen, Paul E.; Galton, Peter M.
The Molteno, Elliot, and Clarens formations comprise the continental Stormberg Group of the Karoo Basin of South Africa and Lesotho. The Molteno Formation contains a well preserved macro- and microfloral assemblage but apparently no vertebrates; the Elliot and Clarens formations contain abundant vertebrates but virtually no floral remains. The vertebrate taxa represented by skeletal remains are listed and divided into two assemblages - the lower Stormberg (lower Elliot) and upper Stormberg (upper Elliot and Clarens) assemblages. The abundant, diagnosable footprint taxa are revised and their names reduced to eight genera. These ichnotaxa also fall into two biostratigraphic zones that parallel the skeletal assemblages. Comparison of the faunal assemblages with those of the European type section strongly suggests that the lower Stormberg assemblage is Late Triassic (Carnian- Norian) in age while the upper Stormberg assemblage is Early Jurassic (Hettangian-Pliens- bachian) in age. Comparisons with other continental assemblages from other areas suggest that the upper Stormberg (upper Elliot and Clarens formations) assemblage broadly correlates with the upper Newark Supergroup of eastern North America, the Glen Canyon of the southwestern United States, and the lower Lufeng Series of China- all thought to be of Early Jurassic age on the basis of floral and/or radiometric evidence. Based on these correlations, previously published paleobiogeographic maps are revised; these show a shift from Late Triassic floral and faunal provinciality to Early Jurassic homogeneity. This shift was synchronous with a widening of the equatorial arid zone.
A structural re-interpretation and revision of the type material of the glossopterid ovuliferous fruitification Scutum from South Africa
(Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, 2011-12) Prevec, Rose
The Early Permian glossopterid fructification Scutum, described by Edna Plumstead in the 1950s from the Vereeniging locality in the Karoo Basin of South Africa, was one of the first glossopterid seed-bearing organs to be found in organic attachment to Glossopteris leaves. Examination of the type material necessitated a revision of this plant fossil genus and a re-evaluation of described South African species. Key characteristics of the genus are the broad and prominent wing, and a low receptacle length to width ratio (<2:1). Specimens of South African Scutum are currently attributed to three species, from two localities, but display intergrading morphological features that can be reasonably accommodated within a single species, S. leslii. Three-dimensional interpretation and reconstruction of impression fossils of Scutum fructifications preserved in attachment to Glossopteris leaves confirms that the seed-bearing surface of the receptacle faces the adaxial surface of the subtending leaf. The nature of the seed scars on the receptacle and their relationship to the peripheral wing of the fructifications is clarified.
A second specimen of Blikanasaurus (Dinosauria: Sauropoda) and the biostratigraphy of the lower Elliot Formation
(Bernard Price Institute for Palaeontological Research, university of the Witwatersrand, 2008-04) Yates, Adam M.
A second specimen of the rare basal sauropod Blikanasaurus cromptoni, is recorded from a site in the Ladybrand district of the Eastern Free State, South Africa. The specimen consists of a right metatarsal 1 that originated from the upper 20mof the lower Elliot Formation. It can be referred to B. cromptoni on the basis of its small size and highly robust proportions, which distinguish this taxon from all other sauropodomorphs. This record extends the geographic distribution of B. cromptoni north into the region of the main Karoo Basin where the Elliot Formation is dramatically thinner. It also extends the known stratigraphic range of B. cromptoni up from the base of the Elliot Formation into a position near the top of the lower member. This new record, combined with other new discoveries, supports the hypothesis that the thin northern part of the lower Elliot Formation is a condensed section that is largely, if not entirely, coeval with the thicker southern sections.

Palaeontologia africana

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