Oculudentavis khaungraae (Xing et al. 2020; Cenomanian, Early Cretaceous 99mya; 1.4cm skull) was originally considered a tiny basal bird with teeth preserved in amber, but here it nests with the basal fenestrasaur, Cosesaurus as a late surviving member of the Middle Triassic radiation that produced Sharovipteryx, Longisquama and pterosaurs like Bergamodactylus. All of these are fenestrasaur tritosaur lepidosaurs. These taxa were not tested when the authors assumed the specimen was a tiny bird and the smallst Mesozoic dinosaur. Ironically the authors noted the lepidosaur-like sclerotic (eyeball) bones and the acrodont to pleurodont teeth, as in modern lizards.
Distinct from Cosesaurus, the palate is solid below the rostrum. The antorbital fenestra is reduced. Damage to the skull displaced one ectopterygoid to the mid palate and broke the jugal. The post-crania remains unknown. Images above from Xing et al. 2020 with colors applied here.
The original description of sister taxon, Cosesaurus (Ellenberger and de Villalta 1974) also mistakenly described it as a basal bird.
Later Li et al. 2020 determined that Oculudentavis was an undetermined lepidosaur. |
