Pterosaur teeth from the Southern Neuquén Basin (Patagonia, Argentina): new insights on the reconstruction of ornithocheiriform dental anatomy

CIAFFI, ALESSIO; BELLARDINI, FLAVIO

ACTA PALAEONTOLOGICA POLONICA

INST PALEOBIOLOGII PAN

Año: 2024 vol. 69

0567-7920

The pterosaur fossil record of Argentina is increasing in recent times, both in the number of localities and their temporalrange. The new materials are found in levels that span from the Late Triassic to the Late Cretaceous in age. In thiscontribution we describe twenty isolated pterosaur teeth from the Cerro de los Leones locality (Picún Leufú, NeuquénProvince), where the Lohan Cura Formation (Albian) widely crops out. A new, detailed analysis of these remains allowedus to detect a set of morphological features, such as the enamel texture, cross-section shape, crown curvature, and absenceof sharp carinae, which suggests close affinities with Ornithocheiriformes. Moreover, with the large number of toothspecimens, a discrimination of three morphotypes based on the crown curvature, the basal cross-section shape, and thepresence of carinae was carried out. We performed extensive morphological comparisons between different members ofOrnithocheiriformes with the aim to test the hypothesis that the presence of these different morphotypes reflects distinctanatomical positions of the teeth in the jaws . Thus, considering the heterodont dentition of ornithocheiriforms, the toothmorphological classification proposed here represents a new methodology, not only to identify isolated ornithocheiriformteeth, but also to assign them to the rostral, medial, or the posterior portion of the tooth row. Finally, the evidence ofornithocheiriform pterosaurs in Cerro de los Leones has paleobiogeographical implications, allowing us to correlate itwith other Albian faunas from South America, expanding our knowledge of the distribution of Early Cretaceous pterosaursacross southwestern Gondwana.