''Brachypterygius'' (meaning ″short wing/paddle″ in Greek) is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of platypterygiine

ophthalmosaurid Ophthalmosauridae is an extinct family of thunnosaur ichthyosaurs from the Middle Jurassic to the early Late Cretaceous (Bajocian - Cenomanian) worldwide. Almost all ichthyosaurs from the Middle Jurassic onwards belong to the family, until the e ...

ichthyosaur Ichthyosauria is an order of large extinct marine reptiles sometimes referred to as "ichthyosaurs", although the term is also used for wider clades in which the order resides. Ichthyosaurians thrived during much of the Mesozoic era; based on fo ...

known from 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 ...

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 ...

.McGowan, C. & Motani, R. ''Ichthyopterygia''. In Sues, H.-D. (ed.) Handbook of Paleoherpetology, vol. 8. Verlag Dr. Friedrich Pfeil, Munich, 175 pp., 19 pls. The

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 ...

was originally described and named as ''

Ichthyosaurus ''Ichthyosaurus'' (derived from Greek () meaning 'fish' and () meaning 'lizard') is a genus of ichthyosaurs from the Early Jurassic (Hettangian - Pliensbachian) of Europe (Belgium, England, Germany and Portugal). Some specimens of the ichthy ...

extremus'' by Boulenger in 1904.Boulenger, G. A. 1904. Exhibition of, and remarks upon, a paddle of a new species of ichthyosaur. ''Proceedings of the Zoological Society of London'', 1904, 424–426. ''Brachypterygius'' was named by Huene in

1922 Events January * January 7 – Dáil Éireann (Irish Republic), Dáil Éireann, the parliament of the Irish Republic, ratifies the Anglo-Irish Treaty by 64–57 votes. * January 10 – Arthur Griffith is elected President of Dáil Éirean ...

for the width and shortness of the forepaddle, and the type species is therefore ''Brachypterygius extremus''.Huene, F. F. von 1922. ''Die Ichthyosaurier des Lias und ihre Zusammenhänge''. Verlag von Gebrüder Borntraeger, Berlin, 114 pp., 22 pls. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

of ''B. extremus'' was originally thought to be from the

Lias Group The Lias Group or Lias is a lithostratigraphic unit (a sequence of rock strata) found in a large area of western Europe, including the British Isles, the North Sea, the Low Countries and the north of Germany. It consists of marine limestones, ...

Bath Bath may refer to: * Bathing, immersion in a fluid ** Bathtub, a large open container for water, in which a person may wash their body ** Public bathing, a public place where people bathe * Thermae, ancient Roman public bathing facilities Plac ...

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

, but other specimens suggest it more likely came from the

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 ...

Kimmeridge Clay The Kimmeridge Clay is a sedimentary rock, sedimentary deposit of fossiliferous marine clay which is of Late Jurassic to lowermost Cretaceous age and occurs in southern and eastern England and in the North Sea. This rock formation (geology), form ...

(Late Jurassic) of Kimmeridge Bay,

Dorset Dorset ( ; Archaism, archaically: Dorsetshire , ) is a Ceremonial counties of England, ceremonial county in South West England. It is bordered by Somerset to the north-west, Wiltshire to the north and the north-east, Hampshire to the east, t ...

, UK.

Description

''Brachypterygius'' is a medium-sized ichthyosaur, with a skull length of and a body length up to .McGowan, C. 1976. The description and phenetic relationships of a new ichthyosaur genus from the Upper Jurassic of England. ''Canadian Journal of Earth Sciences'', 13, 668–683. doi:10.1139/e76-070McGowan, C. 1997. The taxonomic status of ''Grendelius mordax'': a preliminary report. ''Journal of Vertebrate Paleontology'', 17, 428–430. doi:10.1080/02724634.1997.10010986 The snout is long, as is characteristic for ichthyosaurs, with larger and more robust teeth, and a relatively smaller eye than ''

Ophthalmosaurus ''Ophthalmosaurus'' (Greek ὀφθάλμος ''ophthalmos'' 'eye' and σαῦρος ''sauros'' 'lizard') is a genus of ichthyosaur known from the Middle-Late Jurassic. Possible remains from the earliest Cretaceous, around 145 million years ago, a ...

''. The basioccipital has a very narrow extracondylar area. The forepaddle may have five or six digits, with the maximum phalangeal count being between 8 and 16. A key feature is the three facets at the

distal Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

end of the

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

; the middle is the smallest and articulates with the intermedium, which clearly separates ''Brachypterygius'' from ''Ophthalmosaurus'', the most common Late Jurassic ichthyosaur.

Taxonomy

The holotype of ''Brachypterygius extremus'' is a single right forepaddle, clearly different from other Late Jurassic ichthyosaurs (e.g. ''Ophthalmosaurus''). ''Brachypterygius'' is closely related to ''

Platypterygius ''Platypterygius'' is a historically paraphyletic genus of platypterygiine ichthyosaur from the Cretaceous period. It was historically used as a wastebasket taxon, and most species within ''Platypterygius'' likely are undiagnostic at the genus or ...

'' and '' Caypullisaurus''.Fernández M. 2007. Redescription and phylogenetic position of ''Caypullisaurus'' (Ichthyosauria: Ophthalmosauridae). ''Journal of Paleontology'' 81 (2): 368-375.

Species previously assigned to ''Brachypterygius''

Owen Owen may refer to: People and fictional characters * Owen (name), including a list of people and fictional characters with the given name or surname Places United States * Owen, Missouri, a ghost town * Owen, Wisconsin * Owen County, Indiana ...

(1840) erected ''Ichthyosaurus trigonus'' based upon a single dorsal vertebra (ANSP 10124) from the Kimmeridge Clay of Westbrook,

Wiltshire Wiltshire (; abbreviated to Wilts) is a ceremonial county in South West England. It borders Gloucestershire to the north, Oxfordshire to the north-east, Berkshire to the east, Hampshire to the south-east, Dorset to the south, and Somerset to ...

, UK.Owen, R. 1840. Report on British Fossil Reptiles. Part I. ''Report of the British Association for the Advancement of Science'', 9, 43–126. The holotype was long thought to be lost until it was rediscovered in 1988. Many specimens were referred to ''Ichthyosaurus trigonus''; Bauer (1898) suggested that – what are now – ''Ophthalmosaurus'', ''Brachypterygius'' and '' Nannopterygius'' should be synonymised into ''Ichthyosaurus trigonus''.Bauer, F. 1898. Die Ichthyosaurier des oberen weissen Jura. ''Palaeontographica'', 44, 283–328. ''I. trigonus'' was included in the new genus ''Macropterygius'' by Huene (1922), who later (1923) made it the type species of the genus. Nowadays, ''I. trigonus'' (and hence ''Macropterygius'') is a nomen dubium because its holotype is indistinguishable from other ophthalmosaurids. (Christopher McGowan and Ryosuke Motani mistakenly stated that ''I. trigonus'' may be synonymous with ''Ophthalmosaurus icenicus'')

Richard Lydekker Richard Lydekker (; 25 July 1849 – 16 April 1915) was a British naturalist, geologist and writer of numerous books on natural history. He was known for his contributions to zoology, paleontology, and biogeography. He worked extensively in cata ...

erected the species ''Ophthalmosaurus cantabridgiensis'' from the

Cambridge Greensand The Cambridge Greensand is a geological unit in England whose strata are earliest Cenomanian in age. It lies above the erosive contact between the Gault Formation and the Chalk Group in the vicinity of Cambridgeshire, and technically forms the l ...

(

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 ...

, Early Cretaceous) of

Cambridge Cambridge ( ) is a List of cities in the United Kingdom, city and non-metropolitan district in the county of Cambridgeshire, England. It is the county town of Cambridgeshire and is located on the River Cam, north of London. As of the 2021 Unit ...

, UK, on the basis of a humerus (NHMUK PV OR 43989). McGowan and Motani (2003) considered it to be a species of ''Brachypterygius'', but a 2014 re-assessment of Cambridge Greensand ichthyosaurs found it to be a

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

indeterminate beyond Ophthalmosaurinae. In 2020, Nikolay Zverkov and Dmitry Grigoriev reassigned this species to '' Maiaspondylus''. A large skull was discovered in the Kimmeridge Clay of Stowbridge,

Norfolk Norfolk ( ) is a Ceremonial counties of England, ceremonial county in England, located in East Anglia and officially part of the East of England region. It borders Lincolnshire and The Wash to the north-west, the North Sea to the north and eas ...

, UK and named as a new genus and species, '' Grendelius mordax'', by McGowan in 1976. More complete material from the Kimmeridge Clay of Kimmeridge Bay indicated that these two species were quite similar, so the two genera were synonymised. In 2003, McGowan & Motani synonymised the two species ''B. extremus'' and ''B. mordax'' into ''B. extremus'', considering differences in the forepaddle to be of insufficient taxonomic value. However, a 2015 publication by Zverkov and colleagues instead found ''Grendelius mordax'' to be sufficiently different from ''Brachypterygius extremus'' to be considered both a separate genus and species.

Phylogeny

The following cladogram shows a possible phylogenetic position of ''Brachypterygius'' in Ophthalmosauridae according to the analysis performed by Zverkov and Jacobs (2020).

References

{{Taxonbar, from=Q1028288 Fossil taxa described in 1922 Late Jurassic ichthyosaurs Late Jurassic reptiles of Europe Ophthalmosauridae Ichthyosauromorph genera

Description

Taxonomy

Species previously assigned to ''Brachypterygius''

Phylogeny

See also

References