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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    The first record of late Permian tetrapods from Namibia
    (Evolutionary Studies Institute, 2023) Mocke, Helke B; Kammerer, Christian F; Smith, Roger M H; Marsicano, Claudia A
    The entire Omingonde Formation in Namibia was previously assigned a Triassic age based on the fossil tetrapod fauna discovered southwest of theWaterberg Plateau. However, recently repatriated and newly collected material suggests that the lowermost part of the Omingonde Formation includes late Permian strata, equivalent in age to the upper Endothiodon Assemblage Zone of the South African Karoo Basin. In this study,we document the first record of late Permian tetrapod fossils from Namibia, and provide brief descriptions of a gorgonopsian skull collected at Mount Etjo in 1996 and the skull of a small dicynodont collected at the same site in 2019, referable to cf. Tropidostoma. This material confirms that there is need for better understanding of the stratigraphy of the Etjo Mountain area, in particular the position and nature of the unconformity between strata of the Permian Endothiodon and the Triassic Cynognathus assemblage zones.
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    The pre-eminence of the Karoo Basin in the knowledge of the Permo-Jurassic cynodonts: a historical synthesis and taxonomical quantification
    (Evolutionary Studies Institute, 2023) Abdala, Fernando; Hendrickx, Christophe; Jasinoski, Sandra C; Gaetano, Leandro C; Liu, Jun
    The search for the ancestors of mammals is historically connected with the extensive Karoo Basin of South Africa. This is because the Karoo features some of the largest exposures of Permo-Jurassic terrestrial deposits in the world and fossil discoveries were made here early in the history of palaeontology. Among the mammal-like lineages that are well-represented in Karoo fossil assemblages are the cynodonts. Originally conceived as a group exclusively containing fossil taxa, Cynodontia was subsequently redefined to include living mammals, and its Permian and early Mesozoic members are now referred to as non-mammaliaform cynodonts. Here we present a historical account of the research programme on non-mammaliaform cynodonts in the Karoo Basin, which represent the most important record of this group in the world. It covers a time spanning from the first named species in 1859 until the present day, which we arbitrarily divided into three periods: the Early Period extending from 1859 until 1932, the Second Period from 1933 to 1982, and the Current Period from 1983 until now. In the context of the global record of named species, we present quantitative analyses documenting the total number of nominal non-mammaliaform cynodont species from the Karoo (including junior synonyms and homonyms) as well as numerical comparison with taxa currently considered valid. Lastly, we compare the record of non-mammaliaform cynodont species from South Africa with other places in the world, such as Argentina and Brazil, which also have a diverse record of this group.
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    Imprint page
    (2023-07)
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    Inside the front cover
    (2023-07)
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    Table of Contents
    (2023-07)
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    The mandible of Compsodon helmoedi (Therapsida: Anomodontia), with new records from the Ruhuhu Basin, Tanzania
    (2023-07) Angielczyk, Kenneth D.; Peecook, Brandon R.; Smith, Roger M. H.
    The emydopoid dicynodont Compsodon helmoedi originally was named from a single skull collected in Daptocephalus Assemblage Zone strata in the South African Karoo Basin. Recently described specimens from the Luangwa Basin, Zambia, have elucidated the species’ cranial morphology and facilitated identification of other historical Karoo specimens. Neither the holotype nor any of the described Zambian specimens preserve a mandible; a referred Karoo specimen preserves a highly damaged mandible, but poor preservation obscures most details.We present an additional Zambian Compsodon specimen that includes an articulated cranium and mandible, and use μCT data to describe the mandible of this taxon for the first time. The mandible has an upturned dentary symphysis; ‘postcanine’ teeth with coarse distal denticles; a shallow, elongate posterior dentary sulcus with medial expansion anterior to the tooth row, and a prominent lateral dentary shelf. Although the mandible is similar to those of Emydops and Pristerodon, it can be differentiated from Emydops by the latter’s more triangular posterior dentary sulcus, and the absence of a rugose muscle scar on the lateral edge of the lateral dentary shelf. It differs from Pristerodon in the absence of a dentary table rostral to the tooth row, the presence of a transverse ridge dividing the lateral dentary shelf into posterior and anterior sections, and the anterodorsal angulation of the lateral dentary shelf. Three fragmentary specimens from the Usili Formation (Ruhuhu Basin) display the same morphotype and represent the first record of Compsodon from Tanzania. The expanding geographic range of Compsodon underscores its potential as a biostratigraphic index fossil, but more information on its stratigraphic and temporal ranges is needed to realize that potential.
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    Revision of the Scylacosauridae (Therapsida: Therocephalia)
    (2023-07) Kammerer, Christian E.
    The abundant, primarily middle Permian therocephalian family Scylacosauridae is comprehensively reviewed and revised. The 33 nominal scylacosaurid species from the Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa are reduced to seven: Alopecodon priscus, Alopecognathus angusticeps, Glanosuchus macrops, Maraisaurus parvus, Pardosuchus whaitsi, Pristerognathus polyodon, and Scylacosaurus sclateri. The scylacosaurid records from the earlier Eodicynodon Assemblage Zone (previously referred to Glanosuchus and Ictidosaurus) are recognized as a new taxon, Eutheriodon vandenheeveri. Scylacosaurid records from the later Endothiodon Assemblage Zone consist of two long-snouted taxa (the long-ranging species A. angusticeps and P. polyodon) and a short-snouted taxon (Hyorhynchus platyceps) possibly restricted to this zone. The revised identifications presented herein demonstrate that there was substantial scylacosaurid turnover between the Tapinocephalus and Endothiodon AZs, corresponding to the end-Guadalupian extinction.
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    Reappraisal of supposed ‘dinocephalian’ specimens expands burnetiamorph diversity in the Guadalupian Tapinocephalus Assemblage Zone of South Africa
    (2023-07) Day, Michael O.; Kammerer, Christian E.
    Burnetiids are a rare, yet seemingly species-rich family of therapsids in the rocks of the Karoo Basin of South Africa. Discoveries over the past 20 years have provided a greater understanding of the morphological variation within the group and have led to differing hypotheses of burnetiid phylogeny and that of their parent clade, Burnetiamorpha. One posits the existence within Burnetiidae of two subclades, Burnetiinae and Proburnetiinae, but this hypothesis invokes lengthy and thus problematic ghost lineages, particularly for proburnetiines. Herewereview and describe cranial material from the Capitanian Tapinocephalus Assemblage Zone that was previously referred to the dinocephalian therapsid Styracocephalus platyrhynchus, showing that it instead represents two new morphotypes of proburnetiine burnetiids. One of these, Nierkoppia brucei gen. et sp. nov., is diagnosed by the autapomorphic presence of a supraorbital boss ‘folded over’ the dorsal margin of the orbit, giving this structure a roughly ‘ear’ or ‘kidney’-shaped appearance; flattened, posteriorly directed squamosal horns; a median frontal boss taller than the supraorbital bosses, reaching itsmaximumheight anterior to them; and massive, rounded nuchal bosses borne on the postparietal and supraoccipital. The other specimen is left in open nomenclature due to incompleteness, but represents a heavily pachyostosed proburnetiine similar to Lende and Leucocephalus. The recovery of proburnetiines within theTapinocephalus Assemblage Zone shortens the ghost lineage of this clade and indicates that a diverse burnetiid fauna was present in the Guadalupian Karoo, comparable to that now known from Tanzania and Zambia.
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    A new specimen of the sauropodomorph dinosaur Ignavusaurus rachelis from the Early Jurassic of Lesotho
    (Evolutionary Studies Institute, 2020-12-11) Bodenham, Ewan H; Barrett, Paul M
    The upper Elliot Formation (?Rhaetian–Sinemurian) of South Africa and Lesotho has yielded a rich fauna of non-avian dinosaurs, which has generally been considered to be dominated by the massopodan sauropodomorph Massospondylus carinatus. However, re-evaluation of the abundant sauropodomorph collections from this unit suggests that the species-richness of upper Elliot sites has been underestimated. Here, we describe a series of cervical and dorsal vertebrae collected from Likhoele Mountain, Lesotho, which are referred to the rare upper Elliot sauropodomorph taxon Ignavusaurus rachelis. This material represents only the second-known specimen of this taxon, extending its geographic range, and underscores the value of undertaking detailed re-assessments of neglected historical collections.
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    Pleistocene vertebrate trace fossils of Robberg Nature Reserve
    (Evolutionary Studies Institute, 2019-12) Helm, Charles W.; Cawthra, Hayley C.; Hattingh, Rudolph; Hattingh, Sinèad; McCrea, Richard T.; Thesen, Guy H. H.
    More than 140 Late Pleistocene trace fossil sites have been identified in aeolianites and lithified foreshore deposits along a 350 kilometre stretch of the Cape south coast in South Africa. Robberg Nature Reserve lies within this area and contains a zone of concentration of such tracksites, which complement the Pleistocene vertebrate body fossil record and assist in shedding light on the palaeoenvironment and palaeoecology of the Palaeo-Agulhas Plain. Ichnofossil sites unique to or of special significance within Robberg Nature Reserve include a substantial palaeosurface exposure that allows an estimate of track density, the best-preserved rhinoceros trackway identified to date, very well preserved artiodactyl tracks in the formof natural casts, small equid tracks, large elephant transmitted tracks, and well preserved sub-surface golden mole burrows with a burrow chamber. Aeolianite layers at Robberg have recently been dated to Marine Isotope Stage (MIS) 3. Samples that we have obtained for dating from the main palaeosurface underlie these dated layers and are anticipated to contribute to the understanding of the Pleistocene geology of the Robberg Peninsula. The protected status of the area lends itself to conservation, replication, interpretation and education initiatives.