Anurognathidae
Anurognathidae is a family of small, short-tailed pterosaurs that lived in Europe, Asia, and possibly North America during the Jurassic and Cretaceous periods. Eight genera are definitively known: Anurognathus, from the Late Jurassic of Germany; Jeholopterus, Luopterus, Cascocauda and Sinomacrops, from the Middle to Late Jurassic of China; Batrachognathus, from the Late Jurassic of Kazakhstan; and Dendrorhynchoides and Vesperopterylus, from the Early Cretaceous of China. Bennett suggested that the holotype of Mesadactylus, Brigham [Young University Museum of Paleontology|BYU] 2024, a synsacrum, belonged to an anurognathid, though this affinity has been questioned by other authors. Mesadactylus is from the Late Jurassic Morrison Formation of the United States. Indeterminate anurognathid remains have also been reported from the Middle Jurassic Bakhar Svita of Mongolia and the Early Cretaceous of North Korea. Anurognathids had wingspans of up to 900 mm.
Classification
A family Anurognathidae was named in 1928 by Franz Nopcsa von Felső-Szilvás with Anurognathus as the type genus. The family name Anurognathidae was first used by Oskar Kuhn in 1967.The phylogeny of Anurognathidae is disputed. Both Alexander Kellner and David Unwin in 2003 defined the group as a node clade: the last common ancestor of Anurognathus and Batrachognathus and all its descendants. Some analyses, such as that of Kellner, place them as the most basal group in the pterosaur tree. Unwin also recovered the group as very basal, falling between Dimorphodontidae and Campylognathoididae. However, anurognathids have some characteristics in common with the derived Pterodactyloidea, such as short and fused tail bones. More recent analyses, which include more fossils and taxa, support this observation and recover the group as substantially more derived than previously thought, but still basal to pterodactyloids. In 2010 an analysis by Brian Andres indicated the Anurognathidae and Pterodactyloidea were sister taxa. This conformed better to the fossil record because no early anurognathids were known at the time, and being the basalmost pterosaur clade would require a ghost lineage of over sixty million years. However, the reassignment of "Dimorphodon ''weintraubi" to a basal position within Anurognathidae helps fill this gap and suggests this group appeared earlier than previously thought, possibly in the Early Jurassic Period. Depending on where Anurognathidae falls within the Pterosauria, the existence of "Dimorphodon weintraubi" may have important implications for the timing of the evolution of major pterosaur clades, making further study of this specimen critical for pterosaur research. In 2022, a phylogenetic analysis accompanying the description of Cascocauda'' recovered Anurognathidae as a sister clade to Breviquartossa.