New Miocene frogs from the Riversleigh World Heritage Area, north-western Queensland, and their palaeoecological implications

The Riversleigh World Heritage fossil deposits in northwestern Queensland, Australia, preserve diverse vertebrate faunas spanning the last 25 million years. Fossil anurans have been recorded from Riversleigh’s Late Oligocene to Holocene deposits, but they remain understudied. Herein we describe fossil ilia that represent several new undescribed species of fossil frogs referable to the Australian native families Limnodynastidae and Pelodryadidae. Using micro-computed tomography scans and three-dimensional geometric morphometrics (3D GM), we were able to compare the shape of the diagnostic ilium for three of the Riversleigh fossil species of <i>Litoria</i> with extant congeners. Principal component analysis (PCA) and canonical variate analysis (CVA) were performed to assess the differences in ilial shape between supraspecific groups of modern Australian frogs. Our CVA accurately predicted group membership for family up to 99.1% and 89.6% for original and cross-validation, respectively. We describe the new <i>Philoria godthelpi</i> sp. nov. using taxonomic features with extant congeners and add three new morphotypes of <i>Litoria</i> species to the Riversleigh World Heritage Area fauna. These new morphotypes add to our understanding about Australia’s past frog fauna and provide significant insights into their previous diversity, palaeohabitats and palaeobiogeography.