Wits Evolutionary Studies Institute (ESI)

Permanent URI for this community

https://wiredspace.wits.ac.za/handle/10539/13252

Browse

Browsing Wits Evolutionary Studies Institute (ESI) by Faculty "Faculty of Science"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    A new middle Permian burnetiamorph (Therapsida: Biarmosuchia) from the South African Karoo filling a gap in the biarmosuchian record
    (The Evolutionary Studies Institute, 2024-09) Matlhaga, Fonda; Benoit, Julien; Rubidge, Bruce S
    Biarmosuchia, the most basal therapsid clade, is represented by relatively few specimens known from Permian deposits in Russia and southern Africa. In both the Guadalupian (middle Permian) and Lopingian (late Permian), biarmosuchians represent less than 1% of the fossil record at the specimen level. Here, we describe a new burnetiamorph biarmosuchian, Impumlophantsi boonstrai, based on a partial skull and associated postcrania from the upper Tapinocephalus Assemblage Zone. It is characterized by the presence of a low nasal crest with a unique morphology among burnetiamorphs. Inclusion of this taxon in an updated phylogenetic analysis of biarmosuchians indicates that this specimen is one of the most basal burnetiamorphs, representing the only record of this grade from the middle Permian.
  • Thumbnail Image
    Item
    Biostratigraphic refinement of tetrapod-bearing beds from the Metangula Graben (Niassa Province, Mozambique). New radiometric dating and the first Lower Triassic tetrapod fossils from Mozambique
    (Evolutionary Studies Institute, 2020-12) Aráujo, Ricardo; Macungo, Zanildo; Smith, Roger M H; Tolan, Stephen; Angielczyk, Kenneth D; Crowley, James; Milisse, Dino; Mugabe, João
    Numerous fossils of the toothed dicynodont Endothiodon have been collected previously from the Permian K5 formation of the Metangula Graben (Niassa, Mozambique). However, no identifiable vertebrate fossils have been reported from other stratigraphic units in the basin. Here we report likely Triassic tetrapod remains from the base of the Fubué Formation some 700 stratigraphic metres above the dated K5 Formation. We present anatomical comparisons and a phylogenetic analysis that confirm that they have close affinities to the well-known Early Triassic dicynodont therapsid Lystrosaurus. Thus, the Metangula Graben can now join the few regions in the world that preserve terrestrial tetrapod fossils from before and after Permian-Triassic mass extinction event, giving it the potential to provide further insights into the evolution of terrestrial organisms during this major biotic crisis. We present an updated geological section and paleoenvironmental interpretations, as well as the first assessment of the vertebrate taphonomy of the K5, K6, Mount Lilonga, and Fubué Formations. We also report the first radiometric dates for the K5c member of the K5 formation. The K5c has a maximum depositional age of 258.85 ± 0.41 Ma and is thus older than previously thought, falling near the boundary between the Lycosuchus-Eunotosaurus and Tropidostoma-Gorgonops subzones of the Endothiodon Assemblage Zone, rather than being coeval with the Cistecephalus Assemblage Zone.
  • No Thumbnail Available
    Item
    Complete Volume
    (The Evolutionary Studies Institute, 2023-12-21)
    This file contains the complete downloadable volume including all papers, prefaces, and remembrances. Two versions are available: a larger version with embedded videos and a smaller version without.
  • Thumbnail Image
    Item
    Cranial morphology of Jonkeria truculenta (Therapsida, Dinocephalia) and a taxonomic reassessment of the family Titanosuchidae
    (The Evolutionary Studies Institute, 2024-06) Jirah, Sifelani; Rubide, Bruce S; Abdala, Fernando
    Titanosuchidae are a group of herbivorous, long-snouted dinocephalians with definitive records known only from the middle Permian Tapinocephalus Assemblage Zone of the Beaufort Group (Karoo Supergroup) of South Africa. Here, the taxonomy of this family is revised; of the nine species currently recognized, only two are found to be valid: Titanosuchus ferox and Jonkeria truculenta, which can be distinguished on the basis of appendicular proportions. Jonkeria boonstrai, J. haughtoni, J. ingens, J. parva, J. rossouwi, and J. vanderbyli are synonymized with Jonkeria truculenta, and J. koupensis is considered a nomen dubium (Titanosuchidae indet.). Several new cranial features are described for J. truculenta, such as pachyostosis of the prefrontals, postorbitals and parietals, and an ontogenetic series for the species is presented.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    On the importance of using standardized anatomical terminology in palaeoanthropology: The missing StW 431 pubic body
    (The Evolutionary Studies Institute, 2024-09) VanSickle, Caroline; Zipfel, Bernhard
    In 1987, a partial right pubic bone, StW 431ef, was unearthed with hominin skeletal remains at Sterkfontein Cave, South Africa. It preserved the lateral portion of the superior pubic ramus, yet has been described in the literature as a “pubic body”. We confirmed that no medial pubic fragments were discovered with this fossil and sought to explain why it has been described this way. We found that international anatomical terminology guidelines for humans define the pubic body with medial elements, while veterinary guidelines associate it with the portion near the acetabulum We suggest that as a hominin, the StW 431ef pubis should be described based on the human standards, and is thus the lateral portion of a superior pubic ramus. This case illustrates the importance of palaeoanthropologists agreeing on which international standard to follow to ensure clarity and accuracy across disciplines and over time.
  • Thumbnail Image
    Item
    Taxonomic and taphonomic interpretations of newly excavated in situ GD 2 faunal remains at Gondolin
    (The Evolutionary Studies Institute, 2024-01) Engelbrecht, Micke; Val, Aurore; Kibii, Job M.; Steininger, Christine
    Gondolin is one of the fossil-bearing karstic localities in the Cradle of Humankind, South Africa. Periodic excavations of calcified and decalcified sediments at several loci (GD 1,GD2 andGDA) over the last few decades have yielded a sizeable sample of Plio-Pleistocene fauna, including two hominin teeth from ex situ deposits. In 2015, renewed excavations were conducted at the GD 2 locality, which consists of decalcified in situ deposits, in order to shed more light on the site’s complex formation processes as well as to try finding new hominin material from a stratigraphically secured context. While these excavations did not yield any hominin material, abundant macrovertebrate remains were recovered. This paper presents the taxonomic composition and taphonomic characteristics of this new faunal assemblage. The occurrence of Equus sp. as well as the extinct species Metridiochoerus andrewsi and Hystrix makapanensis places the assemblage in a depositional age bracket of 2.33–1.78 Ma, which is consistent with ages already proposed forGD2. No primate material was recovered. The assemblage displays a taxonomic and bodyweight bias towards small-bodied (size classes I and II) bovids. The taphonomic characteristics of the bovid remains suggest the selective action of a leopard-like carnivore and while there is no direct evidence that the locality was used as a hyaena den, secondary scavenging by hyaenids cannot be excluded. Porcupines played an ancillary role in the bone accumulation. We performed intra- and inter-site taxonomic and taphonomic comparisons between this faunal sample and fossil assemblages from previously excavated localities at Gondolin (GD 1, GD 2 and GD A), as well as from other Paranthropus robustus-bearing sites in the Cradle of Humankind. These comparisons indicate that this new sample closely resembles the faunal assemblage previously collected from in situ calcified sediments at the GD 2 locality, in terms of species composition, bovid size class distribution, carnivore to ungulate ratio, and general taphonomic characterization.