''Aspidorhynchus'' (from el, ᾰ̓σπίς 'shield' and el, ῥύγχος 'snout') is an extinct genus of

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

from the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

and

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

periods. Fossils have been found in Europe and Antarctica. Aspidorhynchus NT

''Aspidorhynchus'' was a slender, fast-swimming fish, 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 members of the family Lepisosteidae, which are the only surviving members of the Ginglymodi, an ancient holosteian group of ray-finned fish, which first appeared during the Triassic, over 240 million years ago. Gars comprise seven livin ...

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

Aspidorhynchiformes Aspidorhynchiformes (from New Latin "shield-snout forms") is an extinct order of ray-finned fish. It contains only a single family, the Aspidorhynchidae. Members of the group are noted for their elongated, conical rostrums, of varying length, fo ...

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

teleosts Teleostei (; Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts ), is, by far, the largest infraclass in the class Actinopterygii, the ray-finned fishes, containing 96% of all extant species of fish. Teleo ...

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 (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struc ...

, 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 * 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 ships * Ros ...

. 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 The term 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 diss ...

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

Prehistoric fish of Antarctica Prehistoric ray-finned fish genera Middle Jurassic bony fish Late Jurassic bony fish Cretaceous bony fish Middle Jurassic fish of Europe Late Jurassic fish of Europe Cretaceous fish of Europe Fossil taxa described in 1833 Taxa named by Louis Agassiz {{Cretaceous-fish-stub