''Aspidorhynchus'' (from 'shield' and 'snout') is an extinct genus of predatory

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

from the Middle Jurassic to the earliest Cretaceous. Fossils have been found in Europe, Antarctica and the Caribbean. ''Aspidorhynchus'' was a slender, fast-swimming fish, some species reach long, with tooth-lined, elongated jaws. It also had heavy scales and a symmetrical tail. The upper jaw was longer than the lower jaw, ending in a toothless spike. Although it would have looked superficially similar to the present day

gar Gars are an ancient group of ray-finned fish in the family Lepisosteidae. They comprise seven living species of fish in two genera that inhabit fresh, brackish, and occasionally marine waters of eastern North America, Central America and Cuba ...

s, it was not related to them, belonging to the

Aspidorhynchiformes Aspidorhynchidae (from Neo-Latin "shield-snouts") is an extinct Family (biology), family of Actinopterygii, ray-finned fish from the Mesozoic, Mesozoic Era. It is the only member of the Monotypic taxon, monotypic Order (biology), order Aspidorhync ...

, an extinct group of fish noted for their elongated rostrums. Aspidorhynchiformes are generally considered early relatives of

teleost Teleostei (; Ancient Greek, Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts (), is, by far, the largest group of ray-finned fishes (class Actinopterygii), with 96% of all neontology, extant species of f ...

Taxonomy

''Aspidorhynchus'' contains the following species: * †''A. acutirostris'' (

de Blainville Henri Marie Ducrotay de Blainville (; 12 September 1777 – 1 May 1850) was a French zoologist and anatomist. Life Blainville was born at Arques, near Dieppe. As a young man, he went to Paris to study art, but ultimately devoted himself to natur ...

, 1818) (

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

) -

Kimmeridgian In the geologic timescale, the Kimmeridgian is an age in the Late Jurassic Epoch and a stage in the Upper Jurassic Series. It spans the time between 154.8 ±0.8 Ma and 149.2 ±0.7 Ma (million years ago). The Kimmeridgian follows the Oxfordian ...

of Germany (

Nusplingen Limestone The Nusplingen Limestone (German: Nusplingen Plattenkalk) is a Formation (geology), geological formation in Baden-Württemberg, Germany. It preserves fossils dating to the Kimmeridgian age of the Late Jurassic.paleontological site of Cerin) * †?''A. antarcticus'' Richter & Thompson, 1989 -

Tithonian In the geological timescale, the Tithonian is the latest age (geology), age of the Late Jurassic Epoch and the uppermost stage (stratigraphy), stage of the Upper Jurassic Series. It spans the time between 149.2 ±0.7 annum, Ma and 143.1 ±0.6 (mi ...

James Ross Island James Ross Island () is a large island off the southeast side and near the northeastern extremity of the Antarctic Peninsula, from which it is separated by Prince Gustav Channel. Rising to , it is irregularly shaped and extends in a north–so ...

, Antarctica ( Ameghino Formation) * †''A. arawaki'' Brito, 1997 - Oxfordian of

Cuba Cuba, officially the Republic of Cuba, is an island country, comprising the island of Cuba (largest island), Isla de la Juventud, and List of islands of Cuba, 4,195 islands, islets and cays surrounding the main island. It is located where the ...

(

Jagua Formation The Jagua Formation is a Late Jurassic (middle to late Oxfordian (stage), Oxfordian) geologic Formation (geology), formation in the Sierra de los Órganos and Sierra del Rosario mountain ranges in Pinar del Río Province, western Cuba. Plesiosaur ...

) * †''A. crassus'' Woodward, 1890 -

Bathonian In the geologic timescale the Bathonian is an age (geology), age and stage (stratigraphy), stage of the Middle Jurassic. It lasted from approximately 168.2 ±1.2 annum, Ma to around 165.3 ±1.1 Ma (million years ago). The Bathonian Age succeeds ...

of England (

Taynton Limestone Formation The Taynton LimestoneWeishampel, David B; et al. (2004). "Dinosaur distribution (Middle Jurassic, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. ...

) * †''A. euodus'' Egerton, 1845 -

Callovian In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 165.3 ± 1.1 Ma (million years ago) and 161.5 ± 1.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the ...

of England (

Oxford Clay The Oxford Clay (or Oxford Clay Formation) is a Jurassic marine sedimentary rock formation underlying much of southeast England, from as far west as Dorset and as far north as Yorkshire. The Oxford Clay Formation dates to the Jurassic, specific ...

) * †''A. fisheri'' Egerton, 1845 -

Berriasian In the geological timescale, the Berriasian is an age/ stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 143.1 ±0.6 Ma and 137.05 ± 0.2 (million years ago) ...

of England (

Purbeck Group The Purbeck Group is an Upper Jurassic to Lower Cretaceous lithostratigraphy, lithostratigraphic group (stratigraphy), group (a sequence of rock strata) in south-east England. The name is derived from the district known as the Isle of Purbeck in ...

) * †''A. ornatissimus''

Agassiz Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history. Spending his early life in Switzerland, he recei ...

, 1834 - Tithonian of Germany (

Solnhofen Formation 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 ...

) * †''A. sanzenbacheri'' Brito & Ebert, 2009 - Tithonian of Germany (Solnhofen Formation) ''A. antarcticus'' is known from Jurassic remains reworked into the

Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...

Whisky Bay Formation, and was the oldest

neopterygian Neopterygii (from Greek νέος ''neos'' 'new' and πτέρυξ ''pteryx'' 'fin') is a subclass of ray-finned fish (Actinopterygii). Neopterygii includes the Holostei and the Teleostei, of which the latter comprise the vast majority of extant f ...

fossil discovered in Antarctica at the time. However, some studies have instead classified it in ''

Vinctifer ''Vinctifer'' is an extinct genus of prehistoric bony fish erected by David Starr Jordan in 1919. Fossil record This genus is known in the fossil record from the Late Jurassic (Kimmeridgian) to the Aptian stage of the Early Cretaceous epoch (a ...

'', which was later also identified from the same formation. Other species previously classified in ''Aspidorhynchus'', such as ''A. comptoni'', have also since been moved to ''Vinctifer'', whereas others have been moved to ''

Belonostomus ''Belonostomus'' (from , 'dart' and 'mouth') is a genus of prehistoric ray-finned fish that was described by Louis Agassiz in 1844. It is a member of the order Aspidorhynchiformes Aspidorhynchidae (from Neo-Latin "shield-snouts") is an extin ...

''. A potential species, ''A. montissancti'' Gorjanović-Kramberger, 1895 is known from the

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

Slovenia Slovenia, officially the Republic of Slovenia, is a country in Central Europe. It borders Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the south and southeast, and a short (46.6 km) coastline within the Adriati ...

Ecology

Several limestone slabs have been discovered in which fossils of ''

Rhamphorhynchus ''Rhamphorhynchus'' (, from Ancient Greek ''rhamphos'' meaning "beak" and ''rhynchus'' meaning "snout") is a genus of long-tailed pterosaurs in the Jurassic period. Less specialized than contemporary, short-tailed pterodactyloid pterosaurs such ...

'' are found in close association with ''Aspidorhynchus''. In one of these specimens, the jaws of an ''Aspidorhynchus'' pass through the wings of the ''Rhamphorhynchus'' specimen. The ''Rhamphorhynchus'' also has the remains of a small fish, possibly '' Leptolepides'', in its throat. This slab, cataloged as WDC CSG 255, may represent two levels of predation; one by ''Rhamphorhynchus'' and one by ''Aspidorhynchus''. In a 2012 description of WDC CSG 255, researchers proposed that the ''Rhamphorhynchus'' individual had just caught a ''Leptolepides'' while it was flying low over a body of water. As the ''Leptolepides'' was travelling down its

pharynx The pharynx (: pharynges) is the part of the throat behind the human mouth, mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates ...

, a large ''Aspidorhynchus'' would have attacked from below the water, puncturing the left wing membrane of the ''Rhamphorhynchus'' with its sharp

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit ** podium * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ...

. The teeth in its snout were ensnared in the fibrous tissue of the wing membrane, and as the fish thrashed to release itself the left wing of the ''Rhamphorhynchus'' was pulled backward into the distorted position seen in the fossil. The encounter resulted in the death of both individuals, most likely because the two animals sank into an

anoxic Anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia and hypoxia are used in various contexts: * Anoxic waters, sea water, fresh water or groundwater that are depleted of dissolved ox ...

layer in the water body, depriving the fish of oxygen. The two may have been preserved together as the weight of the head of the ''Aspidorhynchus'' held down the much lighter body of the ''Rhamphorhynchus''.

References

{{Taxonbar, from=Q2543417 Prehistoric ray-finned fish genera Aspidorhynchiformes Middle Jurassic bony fish Late Jurassic bony fish Early Cretaceous bony fish Middle Jurassic fish of Europe Late Jurassic fish of Europe Jurassic fish of North America Early Cretaceous fish of Europe Prehistoric fish of Antarctica Mesozoic vertebrates of Antarctica Fossils of England Fossils of France Fossils of Cuba Fossils of Germany Solnhofen fauna Bathonian genus first appearances Callovian genera Kimmeridgian genera Tithonian genera Berriasian genus extinctions Fossil taxa described in 1833 Taxa named by Louis Agassiz