Extended Data Fig. 5: Diagnostic features of the Pebbly Arkose Fm. assemblage, Dande Communal Area.
From: Africa’s oldest dinosaurs reveal early suppression of dinosaur distribution
a–c, Gomphodontosuchine traversodontid cynodont, right dentary, a, lateral, b, medial, c, occlusal view. Gomphodontosuchine synapomorphies96 include: anterolingual cusp of lower postcanines strongly posteriorly inclined, procumbent lower incisors, reduced lower canine, labial cusp widest in transverse row of lower postcanines. d–e, Aetosaur, d, left paramedian osteroderm in dorsal view, e, left ilium in lateral view. Aetosaurian synapomorphies97 include: anterior bar on paramedian osteoderm, radiate pattern of ornamentation on paramedian osteoderm. The triangular preacetabular process of the ilium is similar to many early aetosaurs97,98,99. f–h, Herrerasaurid dinosaur, coracoid, f, lateral, g, medial, h, posterodorsal view. As in other herrerasaurids48,100,101,102, there is a long hook-like posteroventral process and the coracoid foramen is anteroventral to the glenoid. i–k, Possible dicynodont, highly weathered trunk vertebra centrum, i, ?anterior, j, ?posterior, k, ?left lateral view. The size and general shape of the centrum (amphicoelous, anteroposteriorly compressed, articular surfaces taller and wider than body) is consistent with those of kannemeyeriiform dicynodonts103. l, Hyperodapedontine rhynchosaur, large left maxilla in occlusal view. m–o, Hyperodapedontine rhynchosaur, smaller articulated maxillae and premaxillae originally reported by Raath et al.29, m, occlusal n, anterior o, left lateral view. The maxillary groove is a rhynchosaurid synapomorphy104. Hyperodapedontine synapomorphies104 include: broader than deep tooth-bearing area of maxilla; ‘Hyperodapedon clade’ synapomorphies104 include: > 2 tooth rows medial to maxillary groove. This rhynchosaur lacks synapomorphies of the Teyumbaita clade of hyperodapedontine rhynchosaurs (T. sulcognathus105 and T. sp54): two maxillary grooves that extend anteriorly beyond the posterior third of the tooth plate (the Zimbabwean form has only one maxillary groove); maxillary area lateral to main groove narrower than the medial area (also present in H. hunei; proportions reversed in Zimbabwean form). Scale bars 1 cm. ant, anterior; dor, dorsal; lat, lateral.
