Updated geology and vertebrate paleontology of the Triassic Ntawere Formation of northeastern Zambia, with special emphasis on the archosauromorphs

• Published in: Journal of Vertebrate Paleontology
• Main Authors: Peecook, Brandon R., Steyer, Jean-Sébastien, Tabor, Neil, Smith, Roger, M H
• Other Authors: University of Washington Seattle, Centre de Recherche en Paléontologie - Paris (CR2P), Muséum national d'Histoire naturelle (MNHN)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Southern Methodist University Dallas, University of the Witwatersrand Johannesburg (WITS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology; Argentina; Antarc*; Antarctica
• Online Access: https://hal.science/hal-02365909; https://doi.org/10.1080/02724634.2017.1410484

Issue sup1: Memoir 17: Vertebrate and Climatic Evolution in the Triassic Rift Basins of Tanzania and Zambia International audience The two vertebrate fossil assemblages from the ?Middle Triassic Ntawere Formation have been known since the 1960s, but little new work has been done since the description of novel taxa in the 1960s and 1970s. Three recent field seasons have increased vertebrate diversity in the upper Ntawere assemblage and expanded biostratigraphic connections between the lower and upper Ntawere assemblages and assemblages in fossiliferous basins across southern Pangea. The upper Ntawere contains hybodontoid sharks, ptychoceratodontid lungfish, large- and small-bodied stereospondyl amphibians (Cherninia, ‘Stanocephalosaurus,’ Batrachosuchus, a new taxon), stahleckeriid dicynodonts (Sangusaurus, Zambiasaurus), traversodontid and trirachodontid cynodonts (Luangwa, a new species, Cricodon), and at least four archosauromorphs, including a large loricatan pseudosuchian, a shuvosaurid poposauroid, and silesaurid dinosauriforms (Lutungutali), whereas the lower Ntawere contains the cynodonts Cynognathus and Diademodon and species of the dicynodont Kannemeyeria. The lower and upper Ntawere assemblages have been correlated with the middle and upper subzones of the Cynognathus Assemblage Zone of the Karoo Basin, South Africa, into a network of connections between assemblages in modern day Tanzania, Argentina, Brazil, Namibia, Antarctica, and India. Although lower Ntawere correlations are reinforced by the occurrence of Cynognathus, new observations from the upper Ntawere, in combination with field work in Tanzania, Namibia, and Brazil, have shifted the geographic focus of biostratigraphic connection away from the Karoo later in the Triassic. A recent radiometric date from Argentina from below the horizon correlated with both the Karoo and the lower Ntawere places these, and all higher assemblages, into the Carnian Stage of the Late Triassic.