''Myobradypterygius'' is an extinct genus of

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 ...

from the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

(

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 125.77 Ma (million years ago) and 121.4 ± 1.0 Ma (Historically, this stage was placed at 129.4 million to approximately 125 million years ago) It is a ...

Hauterivian The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous Epoch or a stage in the Lower Cretaceous Series. It spans the time between 132.6 ± 2 Ma and 125.77 (million years ago). The Hauterivian is preceded by the Valangi ...

) of

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

and possibly also

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

. One species is known, ''M. hauthali'',Huene, F. von. (1927). Beitrag zur Kenntnis mariner mesozoischer Wirbeltiere in Argentinien. ''Centralblatt für Mineralogie, Geologie und Paläontologie, B'' 1927:22-29. which was once believed to have been a species of ''

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 ...

''.McGowan, C. (1972). The systematics of Cretaceous ichthyosaurs with particuliar reference to the material from North America. ''Contributions to Geology.'' 1972;11:9–29. ''Myobradypterygius'' is thought to have been a small ichthyosaur, with an estimated total body length of .

Discovery and naming

The holotype, MLP 79-I-30-2, a vertebral column and associated forelimbs, was discovered between 1900 and 1925 by Rudolph Hauthal at Nevado de Famatina,

. The specimen was first described by von Huene (1925) and he reconstructed the forelimb, and described it as being related to ''Myopterygius'' (now '' Pervushovisaurus'').Huene, F. von. (1925). Ichthyosaurier aus der Kreide Argentiniens. ''Revista del Museo de La Plata'' 28:234-238. A second specimen, MLP 79-I-30-1, which included a left humerus and a forefin, was described by von Huene (1927) and in the same paper, both specimens were believed to belong to the same species, which was named ''Myobradypoterygius hauthali''. A second species, ''M. mollensis'', was named by Carlos Rusconi (1938) on the basis of specimen MHN-PV 106, a set of vertebrae found in the

Los Molles Formation The Los Molles Formation is a geologic formation of Early to Middle Jurassic age, located at northern and central part of Neuquén Basin at Mendoza Shelf in Argentina Argentina, officially the Argentine Republic, is a country in the s ...

, but it has since been synonymised with ''

'' and was not mentioned in the 2024 reappraisal of the genus. McGowan (1972) synonymised ''M. hauthali'' with ''

'' and created the new name ''Platypterygius hauthali''. Stinnesbeck ''et al.'' (2014) described around forty ichthyosaur specimens from the

Zapata Formation Zapata Formation () is a sedimentary formation of Lower Cretaceous age in the Magallanes or Austral Basin of Argentina and Chile. Much of the formation is folded and faulted as consequence of the Andean orogeny.Fildani et al., 2008 In outcrops o ...

, several of which had previously been assigned to ''Platypterygius'', and assigned several of the specimens to what would later become ''Myobradyopterygius hauthali''. Fernández and Aguirre-Urreta (2005) reviewed the holotype and were the first to determine that it did not belong to ''Platypterygius''. Campos et al. (2024) reinstated the genus ''Myobradyopterygius'' as separate from ''

''.

Classification

In 1925, ''Myobrachyopterygius'' was classified as being similar to '' Perushovisaurus''. In 1972, it was allied with ''

'', and in 2024, ''Myobrachyopterygius'' was classified within

Ophthalmosauridae 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 ex ...

References

{{Portal bar, Paleontology Ichthyosauromorph genera Early Cretaceous ichthyosaurs Barremian genus first appearances Early Cretaceous reptiles of South America Fossil taxa described in 1927 Taxa named by Friedrich von Huene Ophthalmosauridae