''Bandringa'' is an extinct genus of

Elasmobranch Elasmobranchii () is a subclass of Chondrichthyes or cartilaginous fish, including sharks (superorder Selachii), rays, skates, and sawfish (superorder Batoidea). Members of this subclass are characterised by having five to seven pairs of gil ...

known from the Pennsylvanian subperiod of the

Carboniferous period The Carboniferous ( ) is a Period (geology), geologic period and System (stratigraphy), system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago (Myr, Mya), to the beginning of the Permian Period, ...

that was part of the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

family Bandringidae. There is currently a single known species, ''B. rayi'', described in 1969.R. Zangerl. (1969). ''Bandringa rayi'': A New Ctenacanthoid Shark form the Pennsylvanian Essex Fauna of Illinois. ''Fieldiana Geology'' 12:157-169 It is known from exceptionally preserved individuals found in the Mazon Creek Lagerstätte of

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

which dates back to the late Moscovian stage.

Discovery and naming

The holotype (PF 5686), a juvenile, was found by Ray Bandringa in an

ironstone Ironstone is a sedimentary rock, either deposited directly as a ferruginous sediment or created by chemical replacement, that contains a substantial proportion of an iron ore compound from which iron (Fe) can be smelted commercially. Not to be con ...

concretion A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular ...

during the summer of 1967. By 1979, two species from this genus were originally described, ''B. rayi'' and ''B. herdinae'', but the differences between the two were found to be

taphonomic Taphonomy is the study of how organisms decay and become fossilized or preserved in the paleontological record. The term ''taphonomy'' (from Greek , 'burial' and , 'law') was introduced to paleontology in 1940 by Soviet scientist Ivan Efremov t ...

in origin. All Mazon Creek individuals appear to represent juveniles, suggesting the area was a nursery for them. Also supporting this notion are fossilized egg cases found in the same localities, though it is unclear whether they belong to this genus. Adult fossils attributed to ''B. rayi'' have also been found in spoil heaps from Five Points coal mines near

Conesville, Ohio Conesville is a village (United States)#Ohio, village in Coshocton County, Ohio, Coshocton County, Ohio, United States, along the Muskingum River. The population was 328 at the 2020 United States Census, 2020 census. History Conesville is most lik ...

and Cannelton, Pennsylvania, both of which contain the roughly contemporaneous Kittaning Formation of the Allegheny Group.

Description

''Bandringa'' was a unique looking fish. The most noticeable part of this Chondricthyes is its very long snout that made up half of its body''.'' The snout looks similar to that seen in the unrelated

actinopterygian 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 ho ...

fish family

Polyodontidae Paddlefish (family Polyodontidae) are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their titular elongla ...

(

Acipenseriformes Acipenseriformes is an order of basal ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct families Chondrosteidae and Peipiaosteidae. They are the second earliest div ...

). The body of ''Bandringa'' had two dorsal fins, a set of three lower fins (5 in total) and a long tapering Heterocercal

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

. ''Bandringa'' fed by

suction feeding Aquatic feeding mechanisms face a special difficulty as compared to feeding on land, because the density of water is about the same as that of the prey, so the prey tends to be pushed away when the mouth is closed. This problem was first identifi ...

, and using its long snout and needle like spines on its cheek for hunting in murky water. ''Bandringa'' had a long rostrum and may have been analogous to modern

sawfish Sawfish, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish wi ...

. It appears to have fed via suction feeding. Preserved gut contents include articulated

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...

s. The holotype specimen had length about , but the largest known adult specimen, PU19814 is estimated to be more than five times larger than the type specimen. Although ''Bandringa'' is originally described as Ctenacanthiformes, its relationships to other elasmobranchs is currently unclear.''
''

Breeding

''Bandringa'' is one of the few fossil fish that has a well studied breeding cycle. A paper found that the fish lived a lifestyle that was the opposite of

salmon Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the ...

, with the adults living in freshwater areas and the younger ones living in more brackish and saltwater areas, and when fully grown would swim back into the freshwater areas. This makes sense because at the time, the area of

where ''Bandringa'' specimens have been found was a diagonally running stream that ran from freshwater to saltwater areas.

References

Elasmobranchii Prehistoric cartilaginous fish genera Fossil taxa described in 1969 {{paleo-cartilaginous-fish-stub