cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.29850533
title: Permian origins of the Lystrosauridae (Therapsida: Dicynodontia)

description: New material referable to the dicynodont family Lystrosauridae from the Permian of southern Africa is described. Three lystrosaurid species are recognized in the upper Madumabisa Mudstone Formation of the Luangwa Basin, Zambia, of which two are new (<i>Euptychognathus kingae</i>, sp. nov. and <i>Madumabisa opainion</i>, gen. et sp. nov.). Another new taxon, <i>Lystrosauravus bothae</i>, gen. et sp. nov., is described from the <i>Cistecephalus</i> Assemblage Zone of the South African Beaufort Group. The range of <i>Euptychognathus bathyrhynchus</i> is expanded, with new records from Zambia and possibly Zimbabwe. The holotype of the supposed basally branching lystrosaurid <i>Kwazulusaurus shakai</i> is reinterpreted as a juvenile specimen of <i>Lystrosaurus.</i> Inclusion of the new lystrosaurid taxa in a phylogenetic analysis of anomodonts recovers <i>Madumabisa</i> as the sister-taxon to <i>Euptychognathus</i> and <i>Lystrosauravus</i> as the sister-taxon to <i>Lystrosaurus</i>. <i>Madumabisa</i> is a relatively abundant taxon in the uppermost levels of the Madumabisa Mudstone Formation, indicating that lystrosaurids were not uniformly rare prior to habitat disruption surrounding the Permo–Triassic mass extinction, when <i>Lystrosaurus</i> became a hyper-abundant component of terrestrial faunas. The general morphological similarity of the Permian lystrosaurids to <i>Lystrosaurus</i> itself indicates that the unusual cranial morphology of this group did not evolve in response to pressures associated with the mass extinction, but may have been preadaptations aiding its survival.
DOI: 10.6084/m9.figshare.29850533.v1
title: Permian origins of the Lystrosauridae (Therapsida: Dicynodontia)

description: New material referable to the dicynodont family Lystrosauridae from the Permian of southern Africa is described. Three lystrosaurid species are recognized in the upper Madumabisa Mudstone Formation of the Luangwa Basin, Zambia, of which two are new (<i>Euptychognathus kingae</i>, sp. nov. and <i>Madumabisa opainion</i>, gen. et sp. nov.). Another new taxon, <i>Lystrosauravus bothae</i>, gen. et sp. nov., is described from the <i>Cistecephalus</i> Assemblage Zone of the South African Beaufort Group. The range of <i>Euptychognathus bathyrhynchus</i> is expanded, with new records from Zambia and possibly Zimbabwe. The holotype of the supposed basally branching lystrosaurid <i>Kwazulusaurus shakai</i> is reinterpreted as a juvenile specimen of <i>Lystrosaurus.</i> Inclusion of the new lystrosaurid taxa in a phylogenetic analysis of anomodonts recovers <i>Madumabisa</i> as the sister-taxon to <i>Euptychognathus</i> and <i>Lystrosauravus</i> as the sister-taxon to <i>Lystrosaurus</i>. <i>Madumabisa</i> is a relatively abundant taxon in the uppermost levels of the Madumabisa Mudstone Formation, indicating that lystrosaurids were not uniformly rare prior to habitat disruption surrounding the Permo–Triassic mass extinction, when <i>Lystrosaurus</i> became a hyper-abundant component of terrestrial faunas. The general morphological similarity of the Permian lystrosaurids to <i>Lystrosaurus</i> itself indicates that the unusual cranial morphology of this group did not evolve in response to pressures associated with the mass extinction, but may have been preadaptations aiding its survival.
DOI: 10.6084/m9.figshare.29850536
title: Bone histology of a gorgonopsian skeleton from the upper Madumabisa Mudstone Formation, Zambia

description: Gorgonopsians were an iconic group of non-mammalian therapsids that lived during the middle–late Permian, most known for their long, saber-like canine teeth. While not close relatives of mammals, gorgonopsians share a suite of mammalian skeletal traits, but their paleobiology and growth dynamics are poorly understood. Recent histological analyses of South African (Karoo Basin) gorgonopsians show that fast, cyclic growth is typical for the clade, with environmental influences playing a key role. To assess the life history of gorgonopsians outside of the main Karoo Basin, I sampled six skeletal elements from an indeterminate species from the Luangwa Basin of Zambia. My results show that despite excellent surface preservation, the bone tissue of this species has taphonomic overprinting in the form of filamentous and globular structures that may represent bioerosion. Intact bone tissue type varies across elements, leading to differences in growth rates and vascular orientation. Growth is generally composed of parallel-fibered bone with small, longitudinal primary osteons. One growth mark appears in the femur, and growth spurts are indicated by highly vascularized bone in the tibia and radius. The individual had not reached somatic maturity before death. Compared with Karoo Basin gorgonopsians, which exhibit fast, cyclical growth with abundant growth marks, this Zambian specimen grew more slowly with fewer growth marks. This suggests that small- to medium-sized gorgonopsians displayed a range of moderate to fast growth rates during early ontogeny.
DOI: 10.6084/m9.figshare.29850536.v1
title: Bone histology of a gorgonopsian skeleton from the upper Madumabisa Mudstone Formation, Zambia

description: Gorgonopsians were an iconic group of non-mammalian therapsids that lived during the middle–late Permian, most known for their long, saber-like canine teeth. While not close relatives of mammals, gorgonopsians share a suite of mammalian skeletal traits, but their paleobiology and growth dynamics are poorly understood. Recent histological analyses of South African (Karoo Basin) gorgonopsians show that fast, cyclic growth is typical for the clade, with environmental influences playing a key role. To assess the life history of gorgonopsians outside of the main Karoo Basin, I sampled six skeletal elements from an indeterminate species from the Luangwa Basin of Zambia. My results show that despite excellent surface preservation, the bone tissue of this species has taphonomic overprinting in the form of filamentous and globular structures that may represent bioerosion. Intact bone tissue type varies across elements, leading to differences in growth rates and vascular orientation. Growth is generally composed of parallel-fibered bone with small, longitudinal primary osteons. One growth mark appears in the femur, and growth spurts are indicated by highly vascularized bone in the tibia and radius. The individual had not reached somatic maturity before death. Compared with Karoo Basin gorgonopsians, which exhibit fast, cyclical growth with abundant growth marks, this Zambian specimen grew more slowly with fewer growth marks. This suggests that small- to medium-sized gorgonopsians displayed a range of moderate to fast growth rates during early ontogeny.
DOI: 10.6084/m9.figshare.29850539.v1
title: The stratigraphic record of the therocephalian <i>Theriognathus</i> (Synapsida) and its utility as a biostratigraphic index in Karoo-Aged basins

description: The stratigraphic record of the whaitsiid therocephalian <i>Theriognathus</i> in the Karoo basins of southern Africa is reviewed, with special emphasis on biostratigraphic correlations of the Ruhuhu (Tanzania) and Luangwa (Zambia) basins. Historically, tetrapod-bearing horizons in the Usili Formation of Tanzania and upper Madumabisa Mudstone of Zambia have been inconsistently correlated to the <i>Cistecephalus</i> Assemblage Zone (AZ), <i>Daptocephalus</i> AZ, or have not been conclusively subdivided to the level of the Karoo biozonation. Recent collecting in the main Karoo Basin reference section helps to resolve the first (FAD) and last (LAD) appearance datum of <i>Theriognathus</i> and may reconcile the differing opinions on these formation’s age assignments. The relative abundance of <i>Theriognathus</i> peaks in the middle third of its range in the Daggaboersnek Member of the Balfour Formation (lower <i>Daptocephalus</i> AZ), but a new specimen collected from the Oukloof Member in 2020 and a review of prior records confirms the FAD of <i>Theriognathus</i> in the middle <i>Cistecephalus</i> AZ. Refinements to the FAD partly help to reconcile inconsistent age assignments for <i>Theriognathus</i> in the literature, especially for its occurrences in the Ruhuhu and Luangwa basins which have been most recently interpreted as <i>Cistecephalus</i> AZ-equivalent. We suggest that the well-documented genus <i>Theriognathus</i> provides a reliable biostratigraphic index for the Usili Formation and upper Madumabisa Mudstone Formation, and, in conjunction with its associated dicynodont fauna, is most consistent with the upper <i>Cistecephalus</i> to lower <i>Daptocephalus</i> AZ which has been dated as late Wuchiapingian in age (ca. 256–253 Ma).
DOI: 10.25549/whittington-ouc113779269
title: Dedication at wind tunnel, Los Angeles, Calif., 1945

description: 27 photographs of dedication at wind tunnel, Los Angeles, California, 11 May 1945. Client: International Business Machines (Mr. Lawler, 1670 Wilshire). Operator: Brown.
DOI: 10.6084/m9.figshare.29850539
title: The stratigraphic record of the therocephalian <i>Theriognathus</i> (Synapsida) and its utility as a biostratigraphic index in Karoo-Aged basins

description: The stratigraphic record of the whaitsiid therocephalian <i>Theriognathus</i> in the Karoo basins of southern Africa is reviewed, with special emphasis on biostratigraphic correlations of the Ruhuhu (Tanzania) and Luangwa (Zambia) basins. Historically, tetrapod-bearing horizons in the Usili Formation of Tanzania and upper Madumabisa Mudstone of Zambia have been inconsistently correlated to the <i>Cistecephalus</i> Assemblage Zone (AZ), <i>Daptocephalus</i> AZ, or have not been conclusively subdivided to the level of the Karoo biozonation. Recent collecting in the main Karoo Basin reference section helps to resolve the first (FAD) and last (LAD) appearance datum of <i>Theriognathus</i> and may reconcile the differing opinions on these formation’s age assignments. The relative abundance of <i>Theriognathus</i> peaks in the middle third of its range in the Daggaboersnek Member of the Balfour Formation (lower <i>Daptocephalus</i> AZ), but a new specimen collected from the Oukloof Member in 2020 and a review of prior records confirms the FAD of <i>Theriognathus</i> in the middle <i>Cistecephalus</i> AZ. Refinements to the FAD partly help to reconcile inconsistent age assignments for <i>Theriognathus</i> in the literature, especially for its occurrences in the Ruhuhu and Luangwa basins which have been most recently interpreted as <i>Cistecephalus</i> AZ-equivalent. We suggest that the well-documented genus <i>Theriognathus</i> provides a reliable biostratigraphic index for the Usili Formation and upper Madumabisa Mudstone Formation, and, in conjunction with its associated dicynodont fauna, is most consistent with the upper <i>Cistecephalus</i> to lower <i>Daptocephalus</i> AZ which has been dated as late Wuchiapingian in age (ca. 256–253 Ma).
DOI: 10.6084/m9.figshare.29850542
title: Origin of conglomerate-hosted bonebeds at the base of the upper Permian Usili Formation, Ruhuhu Basin, Tanzania

description: A diverse conglomerate-hosted fossil tetrapod assemblage occurs in a ∼4 m-thick interval at the base of the upper Permian Usili Formation in the Ruhuhu Basin, Tanzania. The interval comprises three 0.5–1.5 m-thick erosively based fining-upward sequences. Each begins with a lenticular body of clast to matrix-supported conglomerate capped by a thin bed of massively bedded granule conglomerate and sharply overlain by fine-grained sandstone. Conglomerate intraclasts include abundant spheroidal carbonate nodules with septarian shrinkage cracks, rounded mudstone pebbles, scattered carbonate mud discs and fragments of stromatolitic limestone, all locally-to-regionally sourced from erosion of the underlying Ruhuhu Formation lacustrine and lake-plain deposits. Isolated cranial and postcranial elements of burnetiamorphs, dicynodonts, gorgonopsians, pareiasaurs, and temnospondyls occur scattered within the conglomerate and overlying gritstone beds, becoming abundant in the capping fine-grained sandstone along with silicified tree trunks. Significantly, most bones are preferentially encrusted with hematite, which suggests generally wet soil conditions with seasonal drying, and tree rings show the normal seasonal growth patterns of a humid temperate climate. The basal Usili conglomerates are attributed to a period of tectonic reorientation of the Ruhuhu rift bounding faults resulting in a basin-wide transition from deep lacustrine (upper Ruhuhu Formation) to alluvial plain with an episode of axial river incision and lateral alluvial fan progradation (basal Usili Formation) before subsidence increased to allow floodplain aggradation (lower-to-upper Usili Formation). Taphonomic signatures of most of the bones suggests they were sourced from carcasses lying exposed on terrace surfaces and in alluvial fan channels rather than from reworking of previously fossilized bones.
DOI: 10.6084/m9.figshare.29850542.v1
title: Origin of conglomerate-hosted bonebeds at the base of the upper Permian Usili Formation, Ruhuhu Basin, Tanzania

description: A diverse conglomerate-hosted fossil tetrapod assemblage occurs in a ∼4 m-thick interval at the base of the upper Permian Usili Formation in the Ruhuhu Basin, Tanzania. The interval comprises three 0.5–1.5 m-thick erosively based fining-upward sequences. Each begins with a lenticular body of clast to matrix-supported conglomerate capped by a thin bed of massively bedded granule conglomerate and sharply overlain by fine-grained sandstone. Conglomerate intraclasts include abundant spheroidal carbonate nodules with septarian shrinkage cracks, rounded mudstone pebbles, scattered carbonate mud discs and fragments of stromatolitic limestone, all locally-to-regionally sourced from erosion of the underlying Ruhuhu Formation lacustrine and lake-plain deposits. Isolated cranial and postcranial elements of burnetiamorphs, dicynodonts, gorgonopsians, pareiasaurs, and temnospondyls occur scattered within the conglomerate and overlying gritstone beds, becoming abundant in the capping fine-grained sandstone along with silicified tree trunks. Significantly, most bones are preferentially encrusted with hematite, which suggests generally wet soil conditions with seasonal drying, and tree rings show the normal seasonal growth patterns of a humid temperate climate. The basal Usili conglomerates are attributed to a period of tectonic reorientation of the Ruhuhu rift bounding faults resulting in a basin-wide transition from deep lacustrine (upper Ruhuhu Formation) to alluvial plain with an episode of axial river incision and lateral alluvial fan progradation (basal Usili Formation) before subsidence increased to allow floodplain aggradation (lower-to-upper Usili Formation). Taphonomic signatures of most of the bones suggests they were sourced from carcasses lying exposed on terrace surfaces and in alluvial fan channels rather than from reworking of previously fossilized bones.
DOI: 10.6084/m9.figshare.29850545
title: The first Paleozoic temnospondyl from Zambia: a new species of <i>Rhineceps</i> from the Permian Madumabisa Mudstone Formation, Mid-Zambezi Basin

description: The Permian temnospondyl fossil record of South Africa’s Karoo Basin is well known but preserves a relatively low abundance and low diversity assemblage composed exclusively of rhinesuchids (viz., <i>Lacosaurus</i>, <i>Rhinesuchoides</i>, <i>Rhinesuchus</i>, and <i>Uranocentrodon</i>). Elsewhere in southern Pangea, temnospondyl taxonomic diversity is even lower, with coeval deposits yielding endemic forms such as <i>Rhineceps nyasaensis</i> from the Chiweta Beds of Malawi and <i>Peltobatrachus pustulatus</i> from the Usili Formation of Tanzania. Permian rocks are present in both the Mid-Zambezi and Luangwa basins of Zambia, but neither has yielded diagnostic temnospondyl fossils so far. Here we describe two nearly complete temnospondyl skulls from the lower portion of the upper Madumabisa Mudstone Formation of southern Zambia’s Mid-Zambezi Basin. These medium-sized skulls both show a subtriangular general outline with a well-developed snout, relatively large orbits, very posterolaterally extended tabulars, a small internarial opening on the dorsal surface of the snout, and a large, heart-shaped anteropalatal depression. We refer these specimens to a new species of rhinesuchid, <i>Rhineceps karibaensis</i>, sp. nov., which enlarges the geographic and stratigraphic range of the genus. The results of an updated cladistic analysis suggest that <i>Rhineceps karibaensis</i>, sp. nov. is the sister taxon of <i>Rhineceps nyasaensis</i> from Malawi. Our recognition of a rhinesuchid in southern Zambia increases the diversity of the amphibian fauna in southern Pangea prior to the end-Permian mass extinction and confirms the broad distribution of rhinesuchids across the region.
DOI: 10.6084/m9.figshare.29850545.v1
title: The first Paleozoic temnospondyl from Zambia: a new species of <i>Rhineceps</i> from the Permian Madumabisa Mudstone Formation, Mid-Zambezi Basin

description: The Permian temnospondyl fossil record of South Africa’s Karoo Basin is well known but preserves a relatively low abundance and low diversity assemblage composed exclusively of rhinesuchids (viz., <i>Lacosaurus</i>, <i>Rhinesuchoides</i>, <i>Rhinesuchus</i>, and <i>Uranocentrodon</i>). Elsewhere in southern Pangea, temnospondyl taxonomic diversity is even lower, with coeval deposits yielding endemic forms such as <i>Rhineceps nyasaensis</i> from the Chiweta Beds of Malawi and <i>Peltobatrachus pustulatus</i> from the Usili Formation of Tanzania. Permian rocks are present in both the Mid-Zambezi and Luangwa basins of Zambia, but neither has yielded diagnostic temnospondyl fossils so far. Here we describe two nearly complete temnospondyl skulls from the lower portion of the upper Madumabisa Mudstone Formation of southern Zambia’s Mid-Zambezi Basin. These medium-sized skulls both show a subtriangular general outline with a well-developed snout, relatively large orbits, very posterolaterally extended tabulars, a small internarial opening on the dorsal surface of the snout, and a large, heart-shaped anteropalatal depression. We refer these specimens to a new species of rhinesuchid, <i>Rhineceps karibaensis</i>, sp. nov., which enlarges the geographic and stratigraphic range of the genus. The results of an updated cladistic analysis suggest that <i>Rhineceps karibaensis</i>, sp. nov. is the sister taxon of <i>Rhineceps nyasaensis</i> from Malawi. Our recognition of a rhinesuchid in southern Zambia increases the diversity of the amphibian fauna in southern Pangea prior to the end-Permian mass extinction and confirms the broad distribution of rhinesuchids across the region.
DOI: 10.6084/m9.figshare.29850548
title: <i>Arctops umulunshi</i>, sp. nov. (Therapsida: Gorgonopsia) from the upper Madumabisa Mudstone Formation of Zambia, with new information on gorgonopsian postcranial anatomy

description: The fossil record of Zambian gorgonopsians includes reports from the Madumabisa Mudstone Formation in both the Mid-Zambezi and Luangwa basins. Despite a longer history of collection, previous reports of gorgonopsians from the Luangwa Basin have been restricted to taxonomic lists, with little in the way of voucher specimens or diagnostic features referenced. Here we introduce <i>Arctops umulunshi</i>, sp. nov., the type of which comprises a nearly complete skull and lower jaws, as well as a large portion of the appendicular skeleton and several vertebrae. The skull is robust and broad-snouted, with three maxillary postcanine teeth, a median vomerine ridge that is displaced anteriorly relative to the lateral ridges, and three teeth on the pterygoid transverse flange surrounded by raised rim of bone. Limb proportions suggest a stocky, strongly built carnivore and potentially diagnostic postcranial features include: atlas intercentrum substantially wider than atlas pleurocentrum, at least one accessory ectepicondylar foramen, and ungual phalanx of pedal digit five very reduced. Our phylogenetic analysis finds <i>Smilesaurus</i> as most closely related to <i>A. willistoni</i> + <i>A. umulunshi</i>, with <i>Lycaenops</i> as the immediate outgroup. These three genera are the sister taxon to a large clade including rubidgeines + <i>Arctognathus</i>. Despite less intensive sampling, the upper Madumabisa Mudstone Formation hosts a gorgonopsian diversity approaching that of coeval South African strata, with most of the same genera represented. Continued detailed anatomical work will further refine the tetrapod biogeography of southern Pangea as well as shed light on ecomorphological differences permitting niche partitioning among coexisting gorgonopsian species.
DOI: 10.6084/m9.figshare.29850548.v1
title: <i>Arctops umulunshi</i>, sp. nov. (Therapsida: Gorgonopsia) from the upper Madumabisa Mudstone Formation of Zambia, with new information on gorgonopsian postcranial anatomy

description: The fossil record of Zambian gorgonopsians includes reports from the Madumabisa Mudstone Formation in both the Mid-Zambezi and Luangwa basins. Despite a longer history of collection, previous reports of gorgonopsians from the Luangwa Basin have been restricted to taxonomic lists, with little in the way of voucher specimens or diagnostic features referenced. Here we introduce <i>Arctops umulunshi</i>, sp. nov., the type of which comprises a nearly complete skull and lower jaws, as well as a large portion of the appendicular skeleton and several vertebrae. The skull is robust and broad-snouted, with three maxillary postcanine teeth, a median vomerine ridge that is displaced anteriorly relative to the lateral ridges, and three teeth on the pterygoid transverse flange surrounded by raised rim of bone. Limb proportions suggest a stocky, strongly built carnivore and potentially diagnostic postcranial features include: atlas intercentrum substantially wider than atlas pleurocentrum, at least one accessory ectepicondylar foramen, and ungual phalanx of pedal digit five very reduced. Our phylogenetic analysis finds <i>Smilesaurus</i> as most closely related to <i>A. willistoni</i> + <i>A. umulunshi</i>, with <i>Lycaenops</i> as the immediate outgroup. These three genera are the sister taxon to a large clade including rubidgeines + <i>Arctognathus</i>. Despite less intensive sampling, the upper Madumabisa Mudstone Formation hosts a gorgonopsian diversity approaching that of coeval South African strata, with most of the same genera represented. Continued detailed anatomical work will further refine the tetrapod biogeography of southern Pangea as well as shed light on ecomorphological differences permitting niche partitioning among coexisting gorgonopsian species.