2026-10-14T13:58:27Z https://api.figshare.com/v2/oai

oai:figshare.com:article/33826001 2026-09-15T22:01:59Z category_8 category_13 category_24 category_272 category_39 category_734 category_132 portal_87 item_type_3 month_year_09_2026

Craniomandibular osteology of <i>Dinodontosaurus isiyavamanda</i> sp. nov. (Therapsida: Anomodontia) from the Manda Beds of Tanzania and new support for a younger age for the alleged oldest dinosaurs Hady George (18410464) Juan A. Escobar (24958871) Edmund R.R. Moody (17878238) Charles B. Saanane (24958874) Michael O. Day (8026037) Nigel R. Larkin (24958877) Microbiology Genetics Evolutionary Biology Environmental Sciences not elsewhere classified Ecology Biological Sciences not elsewhere classified Infectious Diseases upper lifua member representing different adaptations predominantly bulbous posterior phylogenetic analyses conducted midline groove along median palatal ridge otherwise south american new dicynodont taxon alleged oldest dinosaurs tanzanian material possesses dinodontosaurus isiyavamanda </ south american isiyavamanda </ new taxon oldest dinosaurs dinodontosaurus </ oldest records new support dinosaurs globally shansiodon </ cynognathus </ “ tab unique palate triassic tetrapods temporal bar resource partitioning parsimony support manda beds late ladinian known dicynodonts greatly informed food processing craniomandibular osteology confidently interpreted coeval dicynodonts chañares formation bayesian estimation assemblage zone <p>Fossils from the Manda Beds of Tanzania have greatly informed on the diversity and evolution of Triassic tetrapods, including on what might be the oldest dinosaurs. Here, a new dicynodont taxon from the Manda Beds is described. It lacks key anatomical traits of known dicynodonts from the Manda Beds, as well as the Sino-African genus <i>Shansiodon</i> to which some of this material was previously referred. The new taxon is referred to the otherwise South American <i>Dinodontosaurus</i> based on the diagnostic presence of frontals with “tab-like” anterior processes and a combination of other traits seen in the genus. This Tanzanian material possesses a predominantly bulbous posterior/median palatal ridge of the premaxilla and a midline groove along the temporal bar, among other traits that are absent in the South American <i>Dinodontosaurus</i> material, indicating it represents a distinct species, here named <i>Dinodontosaurus isiyavamanda</i> sp. nov. Phylogenetic analyses conducted with Bayesian estimation and parsimony support the inclusion of this species in <i>Dinodontosaurus</i>. The unique palate of <i>D. isiyavamanda</i> is hypothesized to be related to resource partitioning, representing different adaptations for food processing than coeval dicynodonts. The presence of <i>Dinodontosaurus</i> suggests the mid-to-upper Lifua Member of the Manda Beds is equivalent to the <i>Dinodontosaurus</i> Assemblage Zone of Brazil and the Chañares Formation of Argentina. Consequently, the mid-to-upper Lifua Member, which includes what are possibly the oldest records of dinosaurs globally, can be confidently interpreted as late Ladinian to Carnian in age, supporting recent research questioning its equivalency with the <i>Cynognathus</i> Assemblage Zone of South Africa.</p> 2026-09-15T22:01:59Z Dataset Dataset 10.6084/m9.figshare.33826001.v1 https://figshare.com/articles/dataset/Craniomandibular_osteology_of_i_Dinodontosaurus_isiyavamanda_i_sp_nov_Therapsida_Anomodontia_from_the_Manda_Beds_of_Tanzania_and_new_support_for_a_younger_age_for_the_alleged_oldest_dinosaurs/33826001 CC BY 4.0