An edentulous frog (Lissamphibia; Anura) from the Upper Cretaceous (Campanian) Dinosaur Park Formation of southeastern Alberta, Canada

Paleontologists have identified a unique, toothless frog species, Tyrrellbatrachus brinkmani, from the Upper Cretaceous Dinosaur Park Formation in Alberta, Canada. This discovery highlights an early instance of independent tooth loss in anurans during the Campanian stage, challenging previous assumptions about dental evolution in Mesozoic amphibians. The study analyzed seven incomplete maxillae, revealing distinctive features such as a reduced crista dentalis and a processus pterygoideus, which exclude it from known families like Gobiatidae and Pipidae. Comparisons with another edentulous Mesozoic anuran, Theatonius, suggest no close relationship between the two genera. This finding represents one of the oldest records of tooth loss in non-pipid anurans, offering new insights into the evolutionary history of frogs during the Late Cretaceous.

Gardner, J. D. (2015). An edentulous frog (Lissamphibia; Anura) from the Upper Cretaceous (Campanian) Dinosaur Park Formation of southeastern Alberta, Canada. Canadian Journal of Earth Sciences, 52(8), 569–580. https://doi.org/10.1139/cjes-2014-0176