Anurognathidae

Anurognathids Temporal range: Middle Jurassic - Late Jurassic, 164–145.5 Ma PreЄ Є O S D C P T J K Pg N
Life restoration of Anurognathus ammoni
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Order:	†Pterosauria
Clade:	†Caelidracones
Family:	†Anurognathidae Nopcsa, 1928
Type species
Anurognathus ammoni Döderlein, 1923
Subgroups
†Anurognathus †Mesadactylus †Batrachognathinae †Batrachognathus †Dendrorhynchoides †Jeholopterus

The Anurognathidae were a group of small pterosaurs, with short tails or tailless, that lived in Europe, Asia, and possibly North America during the Jurassic period. Four genera are known: Anurognathus, from the Late Jurassic of Germany, Jeholopterus, from the Middle to Late Jurassic of China,^[1] Dendrorhynchoides, from the Middle Jurassic^[2] of China, and Batrachognathus, from the Late Jurassic of Kazakhstan. Bennett (2007) claimed that the holotype of Mesadactylus, BYU 2024, a synsacrum, belonged to an anurognathid.^[3] 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.^[4][5]

Classification

Anurognathid skeletons to scale

A family Anurognathidae was named in 1928 by Franz Nopcsa von Felső-Szilvás (as the subfamily Anurognathinae) with Anurognathus as the type genus. The family name Anurognathidae was first used by Oskar Kuhn in 1967. 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.

The phylogeny of the Anurognathidae is uncertain. Some analyses, as those of Kellner, place them very basal in the pterosaur tree. However, they do have some characteristics in common with the derived Pterodactyloidea, such as the short and fused tail bones. In 2010 an analysis by Brian Andres indicated the Anurognathidae and the Pterodactyloidea were sister taxa. This conforms better to the fossil record because no early anurognathids are known and would require a ghost lineage of over sixty million years.^[6]

Lifestyle

Anurognathids are often believed to have been nocturnal or crepuscular akin to bats; The fact that many anurognathids have large eye-sockets supports the theory of living in darkness. Anurognathid teeth suggest they were insectivorous, though some may have had more prey-choices, such as Jeholopterus who is also believed to have been a fish-eater (and was even considered to be a bloodsucker, but this is unlikely).

Notes