Albanerpetontids (Lissamphibia, Albanerpetontidae) from the Aguja Formation (lower Campanian) of West Texas, USA

The Lowerverse local fauna of West Texas, USA, preserves a rare, early Campanian assemblage of microvertebrates from Laramidia. The recovery of 137 fragmentary specimens reveals that albanerpetontids were locally abundant here and also widespread throughout much of the Western Interior of North America by early Campanian time. Both gracile- and robust-snouted species are represented within the assemblage. Among these, the occurrence of Albanerpeton nexuosum is consistent with its occurrence in paracontemporaneous deposits elsewhere in the Western Interior. The referral of two specimens to Albanerpeton sp., cf. Albanerpetongalaktion, strongly suggests that this long-lived taxon was far more widespread during the early Campanian than previously known and its likely occurrence in West Texas represents a significant geotemporal range extension for the species. However, Albanerpeton gracile is seemingly restricted to Judithian “age” deposits in North America and was not identified at Lowerverse. The Lowerverse assemblage supports the current paradigm involving the occurrence of these three named albanerpetontids during middle Campanian – Maastrichtian time in the Western Interior of North America.