Weigeltisauridae

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Weigeltisauridae
Temporal range: Lopingian 259.51–251.9  Ma
SMNK-PAL 2882.png
Skeleton of Weigeltisaurus
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Neodiapsida
Family: Weigeltisauridae
Kuhn, 1939
Genera

Coelurosauravus
Glaurung [1]
Rautiania
Weigeltisaurus

Contents

Synonyms
  • Coelurosauravidae Evans, 1982

Weigeltisauridae is a family of gliding neodiapsid reptiles that lived during the Late Permian, between 259.51 and 251.9 million years ago. Fossils of weigeltisaurids have been found in Madagascar, Germany, Great Britain, and Russia. They are characterized by long, hollow rod-shaped bones extending from the torso that probably supported wing-like membranes. [2] Similar membranes are also found in several other extinct reptiles such as kuehneosaurids and Mecistotrachelos , as well as living gliding lizards, although each group evolved these structures independently.

Skeleton

Coelurosauravus skull Coelurosauravus.svg
Coelurosauravus skull

The skulls and jaws of weigeltisaurids are ornamented with horns and tubercles, including chameleon-like frills. [3] The torso and limbs are slender. The skeletons of weigeltisaurds are lightened by large air spaces (skeletal pneumaticity) within the bones. The phalanges of the hands and feet are elongate contrasting strongly with those of most other primitive diapsids, but are similar to those of modern arboreal lizards. [4] [3] Unique to weigeltisaurids, the group possesses between 25 and 30 pairs of long, hollow rod-like bones, which project from the lower abdomen dubbed "patagials". These have been proposed to be modified gastralia or otherwise a novel bone ossification. [3]

Schematic diagram of Weigeltisaurus jaekeli Weigeltisaurus jaekeli diagram.png
Schematic diagram of Weigeltisaurus jaekeli

Paleobiology

Life restoration of Weigeltisaurus jaekeli Weigeltisaurus reconstruction.png
Life restoration of Weigeltisaurus jaekeli

Weigeltisaurids have been suggested to be arboreal insectivores. [5] Their limb morphology was well adapted for grasping tree bark, including vertical tree trunks. Due to their limb morphology, they were highly adapted for movement in the trees, and would likely have not been capable of moving quickly or efficiently on the ground. [4] The cranial ornamentation may have served a display purpose. [6]

Gliding

The gliding membrane of weigeltisaurids is distinct from those of other gliding reptiles, which are modified ribs originating from the upper-lateral surface of the body. In contrast, in weigeltisaurids, the rods originate from the lower-lateral surface of the body. The furling and unfurling of the gliding membrane were likely controlled by the abdominal muscles. Preserved fossils show that the bony rods had a high degree of flexibility, similar to the ribs of living gliding lizards. Due to the low-wing configuration, it is likely that the gliding surface was angled upwards to increase stability. [3] In living gliding lizards, it has been found that the forelimbs grab hold of the membrane during takeoff, allowing them to adjust their trajectory mid-flight. Similar behaviour has been proposed for weigeltisaurids, [7] which is supported the presence of an additional phalange in the fourth digit of the hands of weigeltisaurids, which would have allowed them to more effectively grasp the wing. [8] In a 2011 study comparing Coelurosauravus and other extinct gliding reptiles to modern Draco species, Coelurosauravus was found to be a less efficient glider than modern Draco due to its larger body size, with a substantial drop in height per glide. [9]

Relationships

Weigeltisaurids have generally been interpreted as neodiapsids that lie outside of Sauria. It has been controversially proposed that they are closely related to the drepanosaurs, a group of arboreal basal neodiapsids native to northern Pangaea during the Late Triassic. The proposed clade containing the two groups was named Avicephala by Senter in 2004. [10] Proposed synapomorphies of the clade include "absence of intercentra in cervical region; absence of intercentra in dorsal region; scapulocoracoid, ratio of anteroposterior length at base of scapular blade to dorsoventral height of scapular blade between 0.4 and 0.25; outer process of fifth metatarsal absent." [3]

Taxonomy

Wapitisaurus from the Early Triassic of North America was initially suggested to be a member of this family, but this was subsequently doubted. A study published in 2023 found that was likely closely related to thalattosaurs instead. [11]

Related Research Articles

<i>Draco</i> (lizard) Genus of lizards

Draco is a genus of agamid lizards that are also known as flying lizards, flying dragons or gliding lizards. These lizards are capable of gliding flight via membranes that may be extended to create wings (patagia), formed by an enlarged set of ribs. They are arboreal insectivores.

<span class="mw-page-title-main">Archosauromorpha</span> Infraclass of reptiles

Archosauromorpha is a clade of diapsid reptiles containing all reptiles more closely related to archosaurs rather than lepidosaurs. Archosauromorphs first appeared during the late Middle Permian or Late Permian, though they became much more common and diverse during the Triassic period.

<span class="mw-page-title-main">Neodiapsida</span> Clade of reptiles

Neodiapsida is a clade, or major branch, of the reptilian family tree, typically defined as including all diapsids apart from some early primitive types known as the araeoscelidians. Modern reptiles and birds belong to the neodiapsid subclade Sauria.

<i>Youngina</i> Extinct genus of reptiles

Youngina is an extinct genus of diapsid reptile from the Late Permian Beaufort Group of the Karoo Red Beds of South Africa. This, and a few related forms, make up the family Younginidae, within the order Eosuchia. Eosuchia, having become a wastebasket taxon for many probably distantly-related primitive diapsid reptiles ranging from the Late Carboniferous to the Eocene, Romer proposed that it be replaced by Younginiformes.

<i>Protorosaurus</i> Extinct genus of reptiles

Protorosaurus is an extinct genus of reptile. Members of the genus lived during the late Permian period in what is now Germany and Great Britain. Once believed to have been an ancestor to lizards, Protorosaurus is now known to be one of the oldest and most primitive members of Archosauromorpha, the group that would eventually lead to archosaurs such as crocodilians and dinosaurs.

<i>Coelurosauravus</i> Extinct genus of reptiles

Coelurosauravus is an extinct genus of gliding reptile, known from the Late Permian of Madagascar. Like other members of the family Weigeltisauridae, members of this genus possessed long, rod-like ossifications projecting outwards from the body. These bony rods were not extensions of the ribs but were instead a feature unique to weigeltisaurids. It is believed that during life, these structures formed folding wings used for gliding flight, similar to living gliding Draco lizards.

<span class="mw-page-title-main">Avicephala</span> Extinct clade of neodiapsid reptiles

Avicephala is a potentially polyphyletic grouping of extinct diapsid reptiles that lived during the Late Permian and Triassic periods characterised by superficially bird-like skulls and arboreal lifestyles. As a clade, Avicephala is defined as including the gliding weigeltisaurids and the arboreal drepanosaurs to the exclusion of other major diapsid groups. This relationship is not recovered in the majority of phylogenetic analyses of early diapsids and so Avicephala is typically regarded as an unnatural grouping. However, the clade was recovered again in 2021 in a redescription of Weigeltisaurus, raising the possibility that the clade may be valid after all.

<i>Claudiosaurus</i> Extinct genus of reptiles

Claudiosaurus is an extinct genus of diapsid reptiles from the Late Permian Sakamena Formation of the Morondava Basin, Madagascar. It has been suggested to be semi-aquatic.

<i>Hovasaurus</i> Extinct genus of reptiles

Hovasaurus is an extinct genus of basal diapsid reptile. It lived in what is now Madagascar during the Late Permian and Early Triassic, being a survivor of the Permian–Triassic extinction event and the paleontologically youngest member of the Tangasauridae. Fossils have been found in the Permian Lower and Triassic Middle Sakamena Formations of the Sakamena Group, where it is amongst the commonest fossils. Its morphology suggests an aquatic ecology.

<i>Weigeltisaurus</i> Extinct genus of reptiles

Weigeltisaurus is an extinct genus of weigeltisaurid reptile from the Late Permian Kupferschiefer of Germany and Marl Slate of England. It has a single species, originally named as Palaechamaeleo jaekeli in 1930 and later assigned the name Weigeltisaurus jaekeli in 1939, when it was revealed that Palaeochamaeleo was a preoccupied name. A 1987 review by Evans and Haubold later lumped Weigeltisaurus jaekeli under Coelurosauravus as a second species of that genus. A 2015 reassessment of skull morphology study substantiated the validity of Weigeltisaurus and subsequent authors have used this genus. Like other Weigeltisaurids, they possessed long rod-like bones that radiated from the trunk that were likely used to support membranes used for gliding, similar to extant Draco lizards.

<span class="mw-page-title-main">Drepanosaur</span> Extinct clade of reptiles

Drepanosaurs are a group of extinct reptiles that lived between the Carnian and Rhaetian stages of the late Triassic Period, approximately between 230 and 210 million years ago. The various species of drepanosaurid were characterized by specialized grasping limbs and often prehensile tails, adaptions for arboreal (tree-dwelling) and fossorial (digging) lifestyles, with some having also been suggested to be aquatic. Fossils of drepanosaurs have been found in Arizona, New Mexico, New Jersey, Utah, England, and northern Italy. The name is taken from the family's namesake genus Drepanosaurus, which means "sickle lizard," a reference to their strongly curved claws.

Sakamena is a village near Betroka in the region of Anosy in Madagascar.

<i>Mecistotrachelos</i> Extinct genus of reptiles

Mecistotrachelos is an extinct genus of gliding reptile from the Late Triassic of Virginia. It is generally interpreted as an archosauromorph, distantly related to crocodylians and dinosaurs. The type and only known species is M. apeoros. This specific name translates to "soaring longest neck", in reference to its gliding habits and long neck. This superficially lizard-like animal was able to spread its lengthened ribs and glide on wing-like membranes. Mecistotrachelos had a much longer neck than other gliding reptiles of the Triassic such as Icarosaurus and Kuehneosaurus. It was probably an arboreal insectivore.

Rautiania is an extinct genus of gliding neodiapsid reptiles belonging to the family Weigeltisauridae. Isolated fossil remains of Rautiania are known from the Late Permian of Russia. The genus is known from two species, Rautiania alexandri and Rautiania minichi, which differ in aspects of their maxilla and parietal bones. Certain Rautiania fossils have helped to reveal certain aspects of weigeltisaurid anatomy and lifestyle which had long alluded paleontologists, such as the component bones of the "crest" at the back of the head, and the large amount of adaptations towards life in the canopies of forests.

<i>Acerosodontosaurus</i> Extinct genus of reptiles

Acerosodontosaurus is an extinct genus of neodiapsid reptiles that lived during the Late Permian of Madagascar. The only species of Acerosodontosaurus, A. piveteaui, is known from a natural mold of a single partial skeleton including a crushed skull and part of the body and limbs. The fossil was discovered in deposits of the Lower Sakamena Formation. Based on skeletal characteristics, it has been suggested that Acerosodontosaurus individuals were at least partially aquatic.

<span class="mw-page-title-main">Kuehneosauridae</span> Extinct family of reptiles

Kuehneosauridae is an extinct family of small, lizard-like gliding diapsids known from the Triassic period of Europe and North America.

The Marl Slate Formation is a geological formation in England. Despite its name, it is mostly dolomite rock. The Marl Slate Formation was formed about 273 to 259 million years ago, during the Guadalupian and Lopingian epochs of the late Permian period of the Earth's geological history. This formation is part of the Zechstein Group of rocks, and is equivalent to the Kupferschiefer of Germany. The Marl Slate Formation contains fossils including the conodont Mesogondolella britannica and the dorypterid fishes Dorypterus and Lekanichthys, as well as the gliding reptile Weigeltisaurus and terrestrial reptile Protorosaurus The Marl Slate Formation outcrops in County Durham and Yorkshire in north-east England.

Glaurung is an extinct genus of weigeltisaurid reptile from the Upper Permian of Germany. The only known species is Glaurung schneideri. Originally considered a specimen of Coelurosauravus, a later study named it as a new genus after noting that it had several unique characteristics relative to other weigeltisaurids. These characteristics included a low skull, small eyes, smooth parietal and squamosal bones, and spiny jugal bones.

<i>Parasaurus</i> Extinct genus of reptiles

Parasaurus is a genus of pareiasaur known from fossils collected in the Kupferschiefer in Germany, dating to the Late Permian (Wuchiapingian). The type species, Parasaurus geinitzi, described by Hermann von Meyer in 1857, was the first pareiasaur ever described. The seven known specimens were redescribed in 2008.

Wapitisaurus is an extinct genus of thalattosaur from the Early Triassic. Its type and only species is Wapitisaurus problematicus. Its remains were discovered in the Vega-Phroso Member of the Sulphur Mountain Formation in British Columbia, Canada.

References

  1. V. V. Bulanov; A. G. Sennikov (2015). "Glaurung schneideri gen. et sp. nov., a New Weigeltisaurid (Reptilia) from the Kupfershiefer (Upper Permian) of Germany". Paleontological Journal. 49 (12): 1353–1364. doi:10.1134/S0031030115120035.
  2. Sennikov, A. G.; Bulanov, V. V. (October 2006). "The first gliding reptiles from the upper Permian of Russia". Paleontological Journal. 40 (5): S567–S570. Bibcode:2006PalJ...40S.567B. doi:10.1134/S0031030106110037. S2CID   84310001.
  3. 1 2 3 4 5 Pritchard, Adam C.; Sues, Hans-Dieter; Scott, Diane; Reisz, Robert R. (2021-05-20). "Osteology, relationships and functional morphology of Weigeltisaurus jaekeli (Diapsida, Weigeltisauridae) based on a complete skeleton from the Upper Permian Kupferschiefer of Germany". PeerJ. 9: e11413. doi: 10.7717/peerj.11413 . ISSN   2167-8359. PMC   8141288 . PMID   34055483.
  4. 1 2 Bulanov, V. V.; Sennikov, A. G. (2010). "New data on the morphology of Permian gliding weigeltisaurid reptiles of Eastern Europe". Paleontological Journal. 44 (6): 682. Bibcode:2010PalJ...44..682B. doi:10.1134/S0031030110060109. S2CID   85212782.
  5. Bulanov, V. V.; Sennikov, A. G. (2006-10-01). "The first gliding reptiles from the upper Permian of Russia". Paleontological Journal. 40 (5): S567–S570. Bibcode:2006PalJ...40S.567B. doi:10.1134/S0031030106110037. ISSN   1555-6174. S2CID   84310001.
  6. Buffa, Valentin; Frey, Eberhard; Steyer, J.-Sébastien; Laurin, Michel (2021-07-12). "A new cranial reconstruction of Coelurosauravus elivensis Piveteau, 1926 (Diapsida, Weigeltisauridae) and its implications on the paleoecology of the first gliding vertebrates". Journal of Vertebrate Paleontology. 41 (2): e1930020. Bibcode:2021JVPal..41E0020B. doi:10.1080/02724634.2021.1930020. ISSN   0272-4634. S2CID   237517962.
  7. Dehling, J. Maximilian (2017-12-13). "How lizards fly: A novel type of wing in animals". PLOS ONE. 12 (12): e0189573. Bibcode:2017PLoSO..1289573D. doi: 10.1371/journal.pone.0189573 . PMC   5728497 . PMID   29236777.
  8. Buffa, Valentin; Frey, Eberhard; Steyer, J.-Sébastien; Laurin, Michel (2022-09-08). "The postcranial skeleton of the gliding reptile Coelurosauravus elivensis Piveteau, 1926 (Diapsida, Weigeltisauridae) from the late Permian Of Madagascar". Journal of Vertebrate Paleontology. 42 (1): e2108713. Bibcode:2022JVPal..42E8713B. doi: 10.1080/02724634.2022.2108713 . ISSN   0272-4634. S2CID   252173865.
  9. McGuire, Jimmy A.; Dudley, Robert (2011-12-01). "The Biology of Gliding in Flying Lizards (Genus Draco) and their Fossil and Extant Analogs". Integrative and Comparative Biology. 51 (6): 983–990. doi: 10.1093/icb/icr090 . ISSN   1540-7063. PMID   21798987.
  10. Senter, Phil (January 2004). "Phylogeny of Drepanosauridae (Reptilia: Diapsida)". Journal of Systematic Palaeontology. 2 (3): 257–268. Bibcode:2004JSPal...2..257S. doi:10.1017/S1477201904001427. ISSN   1477-2019. S2CID   83840423.
  11. Bastiaans, Dylan; Buffa, Valentin; Scheyer, Torsten M. (November 2023). "To glide or to swim? A reinvestigation of the enigmatic Wapitisaurus problematicus (Reptilia) from the Early Triassic of British Columbia, Canada". Royal Society Open Science. 10 (11). Bibcode:2023RSOS...1031171B. doi: 10.1098/rsos.231171 . ISSN   2054-5703. PMC   10646446 . PMID   38026014.