''Gnathosaurus'' (meaning "jawed lizard") is a genus of

ctenochasmatid Ctenochasmatidae is a group of pterosaurs within the suborder Pterodactyloidea. They are characterized by their distinctive teeth, which are thought to have been used for filter-feeding. Ctenochasmatids lived from the Late Jurassic to the Early ...

pterosaur Pterosaurs are an extinct clade of flying reptiles in the order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 million to 66 million years ago). Pterosaurs are the earli ...

containing two species: ''G. subulatus'', named in 1833 from the

Solnhofen Limestone The Solnhofen Limestone or Solnhofen Plattenkalk, formally known as the Altmühltal Formation, is a Jurassic Konservat-Lagerstätte that preserves a rare assemblage of fossilized organisms, including highly detailed imprints of soft bodied organi ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

, and ''G. macrurus'', known from the

Purbeck Limestone Purbeck Marble is a fossiliferous limestone found in the Isle of Purbeck, a peninsula in south-east Dorset, England. It is a variety of Purbeck stone that has been quarried since at least Roman times as a decorative building stone. Geology Str ...

of the UK. Its fossil remains dated back to the

Late Jurassic The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen ...

period.

History of discovery

Fragments of ''Gnathosaurus'' jaws were first discovered in 1832 in the Solnhofen

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

s of southern

but were mistaken for a piece of teleosaurid

crocodile Crocodiles (family (biology), family Crocodylidae) or true crocodiles are large, semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term "crocodile" is sometimes used more loosely to include ...

jaw by

Georg zu Münster Count Georg Ludwig Friedrich Wilhelm zu Münster (; 17 February 1776 – 23 December 1844) was a German paleontologist. Biography Münster was born on 17 February 1776 in Langelage, near Osnabrück. In 1800, he reportedly became a Prussian of ...

, who first named the species ''Crocodilus multidens'' in that year. Soon afterwards,

Hermann von Meyer Christian Erich Hermann von Meyer (3 September 1801 – 2 April 1869), known as Hermann von Meyer, was a German palaeontologist. He was awarded the 1858 Wollaston medal by the Geological Society of London. Life He was born in Frankfurt am ...

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 Carl Albert Oppel (19 December 1831 – 23 December 1865) was a German paleontologist. History He was born at Hohenheim in Württemberg, on 19 December 1831. He first went to the University of Tübingen, where he graduated with a Ph.D. i ...

compared the ''G. subulatus'' jaw fragment to contemporary pterosaurs such as ''

Pterodactylus ''Pterodactylus'' (from ) is a genus of extinct pterosaurs. It is thought to contain only a single species, ''Pterodactylus antiquus'', which was the first pterosaur to be named and identified as a flying reptile and one of the first prehis ...

'' and ''

Ctenochasma ''Ctenochasma'' (meaning "comb jaw") is a genus of Late Jurassic ctenochasmatid pterosaur belonging to the suborder Pterodactyloidea. Three species are currently recognized: ''C. roemeri'' (named after Friedrich Adolph Roemer), ''C. taqueti'', ...

'', and concluded that it was also probably a "flying reptile" rather than a crocodilian.Oppel, A. (1862). ''Paleontologische Mittheilungen aus dem museum der Koenigl, Paleontologische Mittheilungen aus dem museum der Koenigl''. Ebner & Seubert. A more complete skull of an adult pterosaur was found in 1951 and classified as ''Gnathosaurus subulatus''. This slender, 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 . It probably lead a lifestyle akin to that of modern

spoonbill Spoonbills are a genus, ''Platalea'', of large, long-legged wading birds. The spoonbills have a global distribution, being found on every continent except Antarctica. The genus name ''Platalea'' derives from Ancient Greek and means "broad", refe ...

s, wading with its jaws open and closing them upon touching small prey.Wilton, Mark P. (2013). Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press. . Possible juvenile specimens of ''G. subulatus'' may be known from several complete skeletons that had previously been classified as the separate species ''Pterodactylus micronyx''. These specimens have also been referred to the genus ''

Aurorazhdarcho ''Aurorazhdarcho'' is an extinct genus of ctenochasmatoid pterosaur Pterosaurs are an extinct clade of flying reptiles in the order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous ...

'', which may itself be a synonym of ''Gnathosaurus''. ''Gnathosaurus subulatus'' is currently known only from skulls and jaws, and adult ''Aurorazhdarcho micronyx'' is known only from a skeleton lacking a skull, making direct comparisons difficult. Furthermore, in the only

cladistic Cladistics ( ; from Ancient Greek 'branch') is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is ...

analysis to date that tests the relationships of both taxa they are found distinct. However, Bennett (2025) compared fossil material of ''Gnathosaurus subulatus'' with skulls of the largest juvenile specimens of ''Aurorazhdarcho micronyx'', and concluded that ''Aurorazhdarcho micronyx'' is indeed a junior synonym of ''Gnathosaurus subulatus''. An additional large specimen, originally named ''Pterodactylus macrurus'', is known from the

formation of

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

. 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''.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.

Classification

Below is

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

following a topology by Sita Manitkoon and colleagues in a 2025 study; it finds ''Gnathosaurus'' to be most closely related to the genus ''

Tacuadactylus ''Tacuadactylus'' is a genus of ctenochasmatid pterosaur from the Late Jurassic of Uruguay. Discovery and naming A snout found near Batoví was in 2016 reported as a saw fish, the oldest known member of the Pristidae. Subsequently, a CAT-scan ...

''.

References

{{Portal bar, Paleontology, Germany, United Kingdom Late Jurassic pterosaurs of Europe Ctenochasmatoids Solnhofen fauna Taxa named by Christian Erich Hermann von Meyer Fossil taxa described in 1833

History of discovery

Classification

See also

References