Weigeltizaurids [1] ( lat. Weigeltisauridae ) - a family of extinct basal diapside reptiles [1] . The morphology of the family representatives indicates their adaptation to the arboreal lifestyle and planning flights (sacral consolidation, the structure of the hand characteristic of wood forms, pneumatization of the skull bones and elements of the lateral skin fold, etc.).
| † Weigeltisaurids |
Coelurosauravus jaekeli |
| Scientific classification |
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| No rank : | Bilateral symmetrical |
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| International scientific name |
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Weigeltisauridae Kuhn, 1939 |
| Synonyms |
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- Coelurosauravidae Evans, 1982
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Representatives of Weigeltizaurids are known by fossils from the Permian sediments of Madagascar , Germany , Great Britain and Russia [2] [3] [4] . One species, called Wapitisaurus problematicus, was described from the lower Triassic of Canada [5] , but the poor preservation of fossils leaves doubts about its belonging to the family of Weigeltzavrid [1] .
The ability to plan flights for Weigeltisaurids was achieved due to the presence of wide skin membranes on the sides of the body, supported by hollow rod-shaped ossifications (false ribs) [6] . The structure of this formation allowed them to fold the membrane after landing on a substrate and change its position during flight [7] [8] [9] .
The wide distribution of Weigeltisaurids testifies to the same wide distribution in the Late Permian period of sparse high-trunk forests, most suitable for the formation of planning forms and their further territorial settlement [1] .
Almost all Perm representatives of the family, with the exception of recently discovered East European species (genus Rautiania Bulanov et Sennikov, 2006 ), belong to the genus Coelurosauravus . A type species of the genus Coelurosauravus elivensis Piveteau, 1926 is the very first representative of the family [10] [7] . In 1930, J. Weigelt of the Mansfeld schists in Germany described the first representative of the Weigeltizavrid (under the name Palaeochamaeleo jaekeli ) with a well-preserved skull [4] . This sample was subsequently the basis for discussing the position of the group among reptiles, which was interpreted very widely depending on the interpretation by various authors of the structure of the postorbital part of the skull of the specimen [1] . At present, the affiliation of Weigeltisaurids to diapsids is accepted, however, this provision requires further justification [1] . The generic name Palaeochamaeleo was later replaced by Weigeltisaurus O. Kun , who also introduced the Weigeltisauridae family into the system [11] . Over time, S. Evans and H. Haubold re-examined the type materials of the species Coelurosauravus elivensis and Weigeltisaurus jaekeli , and interpreted the differences between the “southern” and “northern” forms insufficient to separate them at the generic level. During this revision, the genus Weigeltisaurus was invalid, and the species C. jaekeli was added to the genus Coelurosauravus , and the name of the family itself was replaced by Coelurosauravidae [12] . Moreover, provision 40.1 of the International Code of Zoological Nomenclature was violated, in connection with which the renaming of the Weigeltisauridae family to Coelurosauravidae was not lawful and in 2010 the Russian paleontologists V. V. Bulanov and A. Sennikov restored the previous name of the family - Weigeltisauridae [1] .
