Gnathosaurus

Summary

Gnathosaurus
Temporal range: Late Jurassic
Gnathosaurus JWPhoto.jpg
Fossil skull referred to G. subulatus
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Order: Pterosauria
Suborder: Pterodactyloidea
Family: Ctenochasmatidae
Subfamily: Gnathosaurinae
Genus: Gnathosaurus
Meyer, 1833
Type species
Gnathosaurus subulatus
Meyer, 1833
Other species
Synonyms

Gnathosaurus (meaning 'jawed lizard') is a genus of ctenochasmatid pterosaurs containing two species: Gnathosaurus subulatus, named in 1833 from the Solnhofen Limestone of Germany, and Gnathosaurus macrurus, known from the Purbeck Limestone of the UK.

Fragments of Gnathosaurus jaw were first discovered in 1832 in the Solnhofen limestones of southern Germany but were mistaken for a piece of teleosaurid crocodile jaw by Georg zu Münster, who first named the species Crocodilus multidens in that year. Soon afterwards, Hermann von Meyer classified the same specimen as the new genus and species Gnathosaurus subulatus, a name which came to be universally used shortly thereafter. In the 1860s, scientists such as Albert Oppel compared the G. subulatus jaw fragment to contemporary pterosaurs such as Pterodactylus and Ctenochasma, and concluded that it was also probably a "flying reptile" rather than a crocodilian.[1] A more complete skull of an adult pterosaur was found in 1951 and classified as Gnathosaurus subulatus. This slender, 28 centimetres (11 in) long skull had up to 130 needle-like teeth arranged around the side of a spoon-shaped tip. The specimen had an estimated wingspan of about 1.7 metres (5.6 ft). It probably lead a lifestyle akin to that of modern spoonbills, wading with its jaws open and closing them upon touching small prey.[2]

Reconstruction of Gnathosaurus subulatus in its environment

Possible juvenile specimens of G. subulatus may be known from several complete skeletons that had previously been classified as the separate species Pterodactylus micronyx.[3] These specimens have also been referred to the genus Aurorazhdarcho, which may itself be a synonym of Gnathosaurus. However, because Gnathosaurus subulatus is currently known only from skulls and jaws, and adult Aurorazhdarcho micronyx known only from a skeleton lacking a skull, the two cannot be confidently referred to the same species.[4] Furthermore, in the only cladistic analysis to date that tests the relationships of both taxa they are found distinct.[5]

An additional large specimen, originally named Pterodactylus macrurus, is known from the Purbeck Limestone formation of England. Represented only by a partial lower jaw and neck vertebrae, it has since been considered closer to Gnathosaurus, and its binomial changed to G. macrurus.[6]

Classification

Cladogram following Andres, Clark & Xu, 2014.[7]

 Ctenochasmatidae 
 Gnathosaurinae 

Kepodactylus insperatus

Elanodactylus prolatus

Feilongus youngi

Moganopterus zhuiana

Huanhepterus quingyangensis

Plataleorhynchus streptophorodon

Gnathosaurus subulatus

Gnathosaurus macrurus

 Ctenochasmatinae 

Ctenochasma

Pterodaustro guinazui

Eosipterus yangi

Beipiaopterus chenianus

Gegepterus changi


Cladogram following the latest version of Andres' data set, published by Longrich, Martill, and Andres in 2018:[8]

Ctenochasmatoidea
Gallodactylidae

Cycnorhamphus suevicus

Normannognathus wellnhoferi

Ctenochasmatidae

Kepodactylus

Moganopterinae

Moganopterus

Feilongus

Ardeadactylus

Elanodactylus

Gnathosaurinae

Huanhepterus

Plataleorhynchus

Gnathosaurus

CtenochasmatinaePterodaustro BW.jpg

See also

References

  1. ^ Oppel, A. (1862). Paleontologische Mittheilungen aus dem museum der Koenigl, Paleontologische Mittheilungen aus dem museum der Koenigl. Ebner & Seubert.
  2. ^ Wilton, Mark P. (2013). Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press. ISBN 0691150613.
  3. ^ Bennett, S.C. (2002). "Soft tissue preservation of the cranial crest of the pterosaur Germanodactylus from Solnhofen". Journal of Vertebrate Paleontology. 22 (1): 43–48. doi:10.1671/0272-4634(2002)022[0043:stpotc]2.0.co;2.
  4. ^ S. Christopher Bennett (2013). "New information on body size and cranial display structures of Pterodactylus antiquus, with a revision of the genus". Paläontologische Zeitschrift. 87 (2): 269–289. doi:10.1007/s12542-012-0159-8.CS1 maint: uses authors parameter (link)
  5. ^ Vidovic, S. U.; Martill, D. M. (2014). "Pterodactylus scolopaciceps Meyer, 1860 (Pterosauria, Pterodactyloidea) from the Upper Jurassic of Bavaria, Germany: The Problem of Cryptic Pterosaur Taxa in Early Ontogeny". PLoS ONE. 9 (10): e110646. doi:10.1371/journal.pone.0110646. PMC 4206445. PMID 25337830.
  6. ^ Howse S. C. B. and Milner A. R., 1995, The Pterodactyloids from the Purbeck Limestone Formation of Dorset. Bull. Nat. Hist. Mus. London. (Geol) 51(1): 73-88.
  7. ^ Andres, B.; Clark, J.; Xu, X. (2014). "The Earliest Pterodactyloid and the Origin of the Group". Current Biology. 24: 1011–6. doi:10.1016/j.cub.2014.03.030. PMID 24768054.
  8. ^ Longrich, N.R.; Martill, D.M.; Andres, B. (2018). "Late Maastrichtian pterosaurs from North Africa and mass extinction of Pterosauria at the Cretaceous-Paleogene boundary". PLoS Biology. 16 (3): e2001663. doi:10.1371/journal.pbio.2001663. PMC 5849296. PMID 29534059.