''Macrosqualodelphis'' 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 ...

river dolphin River dolphins are a polyphyletic group of fully aquatic mammals that reside exclusively in freshwater or brackish water. They are an informal grouping of dolphins, which itself is a paraphyletic group within the infraorder Cetacea. Extant rive ...

s from the

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ...

(Burdigalian) Chilcatay Formation of the

Pisco Basin Pisco Basin () is a sedimentary basin extending over in southwestern Peru.Solís Mundaca, 2018, p.1 The basin has a 2-kilometre (1.25-mile) thick sedimentary fill, which is about half the thickness of more northern foreland basins in Peru. The o ...

, Peru. 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 ...

is ''M. ukupachai''.

Description

''Macrosqualodelphis'' is distinguished from other squalodelphinids by its larger size () and a less abrupt anterior tapering of rostrum in dorsal view, U-shaped left antorbital notch prominent nuchal crest higher than the frontals and nasals at the vertex, a thinner, blade-like lateral margin of the posterior portion of the rostrum, and a more voluminous temporal fossa and larger teeth.Giovanni Bianucci, Giulia Bosio, Elisa Malinverno, Christian de Muizon, Igor M. Villa, Mario Urbina and Olivier Lambert. 2018
"A New Large Squalodelphinid (Cetacea, Odontoceti) from Peru Sheds Light on the Early Miocene Platanistoid Disparity and Ecology"
. Royal Society Open Science. 5(4) DOI: 10.1098/rsos.172302 Material was copied from this source, which is available under
Creative Commons Attribution 4.0 International License

References

Squalodelphinidae Prehistoric toothed whales Miocene cetaceans Miocene mammals of South America Neogene Peru Fossils of Peru Fossil taxa described in 2018 {{Paleo-whale-stub