Анурогнат (Anurognathus от греч. αν — без, греч. оυρα — хвост и греч. γναθος — челюсти) — род малых птерозавров семейства Anurognathidae, представители которого жили около 150 миллионов лет назад в конце юрского периода.

 Род был описан и назван Людвигом Дёдерляйном (Ludwig Döderlein) в 1923 году. Типовым видом является Anurognathus ammoni.

 Представители рода отличаются необычной внешностью по отношению к другим птерозаврам подотряда Рамфоринхоиды. Видовое название ammoni дано в честь баварского геолога Людвига фон Аммона, который собрал коллекцию ископаемых, в которой был и Anurognathus ammoni.

 Анурогнат означает буквально «бесхвостый» или «беззубый» — что ж, вполне понятная, хотя и не совсем точная характеристика применительно к этим необычным птерозаврам. Судить об анурогнатах ученым остаётся только по останкам одной-единственной особи, обнаруженной в Германии в 20-е годы XX века. Хвост у него и правда походил на обрубок, голова была маленькая и тупорылая, а в пасти имелось всего несколько мелких зубов. Зато анурогнаты обладали хорошо развитыми конечностями. Впрочем, наличие таких признаков объясняется тем, что найденные останки принадлежали молодой особи, — у взрослого животного они наверняка были бы другими. Кроме того, анурогнаты, возможно, принадлежали к легким охотникам, и добычей им служили стрекозы и прочие насекомые, которых они отлавливали, прыгая со спин динозавров, используя их как живые трамплины. В размахе крыльев достигали 50 см.

 Anurognathus had a short head with pin-like teeth for catching insects and although it traditionally is ascribed to the long-tailed pterosaur group "Rhamphorhynchoidea", its tail was comparatively short, allowing it more maneuverability for hunting. According to Döderlein the reduced tail of Anurognathus was similar to the pygostyle of modern birds. Its more typical "rhamphorhynchoid" characters include its elongated fifth toe and short metacarpals and neck. With an estimated wingspan of fifty centimetres (20 inches) and a nine centimetre long body (skull included), its weight was limited: in 2008 Mark Paul Witton estimated a mass of forty grammes for a specimen with a 35 centimetre wingspan. The holotype was redescribed by Peter Wellnhofer in 1975.

 Later a second, smaller, specimen was found, probably of a subadult individual. Its slab and counterslab are separated and both were sold to private collections; neither has an official registration. It was described by S. Christopher Bennet in 2007. This second exemplar is much more complete and better articulated. It shows impressions of a large part of the flight membrane and under UV-light remains of the muscles of the thigh and arm become visible. It provided new information on many points of the anatomy. The skull was shown to have been very short and broad, wider than long. It transpired that Wellnhofer had incorrectly reconstructed the skull in 1975, mistaking the large eye sockets for the fenestrae antorbitales, skull openings that in most pterosaurs are larger than the orbits but in Anurognathus are small and together with the nostrils placed at the front of the flat snout. The eyes pointed forwards to a degree, providing some binocular vision. Most of the skull consisted of bone struts. The presumed pygostyle was absent; investigating the real nine tail vertebrae instead of impressions showed that they were unfused, though very reduced. The wing finger lacked the fourth phalanx. According to Bennett a membrane, visible near the shin, showed that the wing contacted the ankle and was thus rather short and broad. Bennett also restudied the holotype, interpreting bumps on the jaws as an indication that hairs forming a protruding bristle were present on the snout.

 The Anurognathidae were a group of small pterosaurs, with short tails or tailless, that lived in Europe and Asia during the Jurassic and early Cretaceous periods. Four genera are known: Anurognathus, from the Late Jurassic of Germany, Jeholopterus, from the Middle or Late Jurassic of China, Dendrorhynchoides, from the Early Cretaceous 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. Mesadactylus is from the Late Jurassic Morrison Formation of the USA. Indeterminate Anurognathid remains have also been reported from the Middle Jurassic Bakhar Svita of Mongolia.

 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.

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Tags: Вымершие рептилии, Юра, авеметатарзалии, анурогнатиды, архозавроморфы, архозавры, диапсиды, птерозавры, рамфоринхоидеи

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