A new sympatric occurrence of lagerpetids (Pan-Aves, Pterosauromorpha) in the upper Triassic of southern Brazil

Abstract

Lagerpetids, traditionally considered precursors to dinosaurs, have recently been hypothesized as being the sister group to Pterosauria, providing clues on the dawn of the flying reptiles from the Mesozoic Era. Here, we describe new lagerpetid specimens from the Upper Triassic of southern Brazil, specifically from the upper Santa Maria Formation, lower Candelária Sequence (Carnian). The new specimens contribute to our understanding of the early evolution and anatomical diversity of pterosauromorphs, shedding light on the ecological and community dynamics during this crucial period. The hindlimb anatomy, particularly of the femur, provides necessary data regarding the understanding of lagerpetid diversity, because this is the only element preserved across all lagerpetid taxa. Phylogenetic analyses and anatomical traits place the new specimens within Lagerpetidae, revealing two possible novel morphotypes coexisting with a third distinct lagerpetid morphotype. The sympatric occurrences of lagerpetids in the Upper Triassic of southern Brazil add to our understanding of pterosauromorph ecology in the Late Triassic and represents one of the few cases of lagerpetid sympatry worldwide, especially in Carnian beds.