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''Allodelphis'' is an
''Allodelphis'' has a very elongated rostrum and a polydont, heterodont dentition. It differs from '' Ninjadelphis'' and '' Zarhinocetus'' in the following characters: wider dorsal opening of mesorostral canal anterior to dorsal nares, posterior part of rostrum anterior to dorsal nares not depressed, posterior ends of premaxillae less irregular and digitated, posterior ends of premaxillae extending posteriorly beyond level of posterior margins of corresponding nasal bones, nasal bones elevated anteriorly rather than tilting anteroventrally into posterior part of dorsal nares, nasal bones expanded in width anteriorly rather than narrow anteriorly, nasal bones not fused to each other at midline or to underlying frontal bones, instead having margins defined clearly by sutures, nasal bones and dorsal exposures of frontal bones at cranial vertex symmetrical, with mid-line sutures on mid-sagittal plane rather than skewed asymmetrically to left side, right and left halves of nuchal crest symmetrical and having approximately equal widths and curvatures, and nuchal crest nearly straight transversely rather than curved anteriorly near cranial vertex; tympanic bulla with less inflated outer lip, and smaller and more posteriorly directed sigmoid process; atlas vertebra having dorsal transverse process tapered and not expanded dorsoventrally.Toshiyuki Kimura and Lawrence G. Barnes (2016). "New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean". Bulletin of the Gunma Museum of Natural History 20: 1–58.
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 ...
of whale
Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and ...
belonging to Allodelphinidae
Allodelphinidae is a family of primitive platanistoid river dolphins found in marine deposits in the eastern North Pacific region, Alaska, and Japan.
Description
Kimura and Barnes (2016, pp. 3–4) diagnose the family as follows:
System ...
found in marine deposits of the eastern North Pacific.
Description
''Allodelphis'' has a very elongated rostrum and a polydont, heterodont dentition. It differs from '' Ninjadelphis'' and '' Zarhinocetus'' in the following characters: wider dorsal opening of mesorostral canal anterior to dorsal nares, posterior part of rostrum anterior to dorsal nares not depressed, posterior ends of premaxillae less irregular and digitated, posterior ends of premaxillae extending posteriorly beyond level of posterior margins of corresponding nasal bones, nasal bones elevated anteriorly rather than tilting anteroventrally into posterior part of dorsal nares, nasal bones expanded in width anteriorly rather than narrow anteriorly, nasal bones not fused to each other at midline or to underlying frontal bones, instead having margins defined clearly by sutures, nasal bones and dorsal exposures of frontal bones at cranial vertex symmetrical, with mid-line sutures on mid-sagittal plane rather than skewed asymmetrically to left side, right and left halves of nuchal crest symmetrical and having approximately equal widths and curvatures, and nuchal crest nearly straight transversely rather than curved anteriorly near cranial vertex; tympanic bulla with less inflated outer lip, and smaller and more posteriorly directed sigmoid process; atlas vertebra having dorsal transverse process tapered and not expanded dorsoventrally.Toshiyuki Kimura and Lawrence G. Barnes (2016). "New Miocene fossil Allodelphinidae (Cetacea, Odontoceti, Platanistoidea) from the North Pacific Ocean". Bulletin of the Gunma Museum of Natural History 20: 1–58.
Taxonomy
Two species are currently recognized, ''A. pratti'' and ''A. woodburnei''. The latter species is found in younger (Early Miocene, Aquitanian) deposits than ''A. pratti'', which is found in the late OligoceneJewett Sand Formation
The Jewett Sand Formation is a geologic formation in California, USA. It preserves fossils dating back to the Miocene Epoch of the Neogene period.
Vertebrates
Cartilaginous fishes
Sharks
200px, Fossil teeth of ''C. hastalis''
*''†Alopias ...
of Kern County
Kern County is a county located in the U.S. state of California. As of the 2020 census, the population was 909,235. Its county seat is Bakersfield.
Kern County comprises the Bakersfield, California, Metropolitan statistical area. The county sp ...
, California.L. G. Barnes and R. E. Reynolds. 2009. A new species of early Miocene allodelphinid dolphin (Cetacea, Odontoceti, Platanistoidea) from Cajon Pass, Southern California, U.S.A. Museum of Northern Arizona Bulletin 65:483-507.
Biology
The nature of the sediments in which ''Allodelphis'' has been found denotes a neritic environment for the genus. The advanced degree of telescoping in the cranium shows that it could track prey using echolocation.References
Prehistoric toothed whales Oligocene cetaceans Miocene cetaceans Prehistoric cetacean genera Fossil taxa described in 1935 {{paleo-whale-stub