''Huaridelphis'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 riv ...

s from the

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was prece ...

(

Deseadan The Deseadan ( es, Deseadense) age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It fo ...

Friasian The Friasian age is a period of geologic time (16.3–15.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Santacrucian and precedes the Colloncuran age. ...

in the SALMA classification). The

type species In 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 species that contains the biological type specimen ...

is ''H. raimondii'', found in the Chilcatay Formation of the

Pisco Basin Pisco Basin ( es, Cuenca de Pisco) is a sedimentary basin extending over in southwestern Peru.Solís Mundaca, 2018, p.1 The basin has a thick sedimentary fill, which is about half the thickness of more northern foreland basins in Peru. The old ...

Etymology

The genus name is derived from the name of the Huari people, an ancient culture from

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

, and from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

word for "dolphin"; ''delphis''. The specific name was chosen in honor of

Antonio Raimondi Antonio Raimondi (September 19, 1826 – October 26, 1890) was a prominent Italian-born Peruvian geographer and scientist. Born in Milan, Raimondi emigrated to Peru, arriving on July 28, 1850, at the port of Callao. In 1851 he became a prof ...

, an Italian geographer and the first person to discover fossilized whale remains in Peru.

Description

''H. raimondii'' was a relatively small squalodelphinid, with a bizygomatic breadth of and a condylobasal length of . The

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 ...

, which was only slightly

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

ly flattened, and made up only 67% of the condylobasal length, considerably less than most squalodelphinids. The antorbital notches were V-shaped and asymmetrical, with the right notch farther back on the head than the left one. The species had 28-30 teeth per top row, with

alveoli Alveolus (; pl. alveoli, adj. alveolar) is a general anatomical term for a concave cavity or pit. Uses in anatomy and zoology * Pulmonary alveolus, an air sac in the lungs ** Alveolar cell or pneumocyte ** Alveolar duct ** Alveolar macrophage * ...

ranging in diameter between . Teeth ranged from high at the

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...

. Ribs measured around .

Discovery

Fossils of ''H. raimondii'' have been recovered from the Chilcatay Formation in Ullujaya and Zamaca, in the

Ica Region Ica (; qu, Ika) is a department and region of Peru. It borders the Pacific Ocean on the west; the Lima Region on the north; the Huancavelica and Ayacucho regions on the east; and the Arequipa Region on the south. Its capital is the city of Ic ...

of Peru.

Habitat

The specimens date from the

. Specimens were found along with fossils of '' Isurus desori'' and '' Carcharocles chubutensis'' (two species of sharks), as well as those of

baleen whales Baleen whales (systematic name Mysticeti), also known as whalebone whales, are a parvorder of carnivorous marine mammals of the infraorder Cetacea (whales, dolphins and porpoises) which use keratinaceous baleen plates (or "whalebone") in their ...

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

, and

sea turtle Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhead, ...

s. Injuries, probably from sharks, were observed on at least two of the fossils.

References

River dolphins Prehistoric toothed whales Miocene cetaceans Miocene mammals of South America Friasian Santacrucian Colhuehuapian Deseadan Neogene Peru Fossils of Peru Fossil taxa described in 2014 {{Paleo-whale-stub