''Indocetus'' is a protocetid early whale known from the late early

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...

(

Lutetian The Lutetian is, in the geologic timescale, a stage or age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it is sometimes referred to as the ...

, ) Harudi Formation (, paleocoordinates ) in Kutch, India. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

of is a partial skull in two pieces with the frontal shield and the right occiput and auditory bulla preserved. described postcranial remains from the

Sulaiman Range The Sulaiman Mountains, also known as Kōh-e Sulaymān ( Balochi/Urdu/ fa, ; "Mountains of Solomon") or Da Kasē Ghrūna ( ps, د كسې غرونه; "Mountains of Kasi"), are a north–south extension of the southern Hindu Kush mountain system i ...

Punjab, Pakistan Punjab (; , ) is one of the four provinces of Pakistan. Located in central-eastern region of the country, Punjab is the second-largest province of Pakistan by land area and the largest province by population. It shares land borders with the ...

, and attributed them to ''Indocetus''. , however, withdrew this assignment and instead attributed this postcranial material to ''

Remingtonocetus ''Remingtonocetus'' is an extinct genus of early cetacean freshwater aquatic mammals of the family Remingtonocetidae endemic to the coastline of the ancient Tethys Ocean during the Eocene. It was named after naturalist Remington Kellogg. History ...

'' because of similarities to the then newly discovered remingtonocetid ''

Dalanistes ''Dalanistes'' is an extinct genus of remingtonocetid early whale known from the late early Eocene (Lutetian, ) of Kutch, India and Punjab and Balochistan, Pakistan. ''Dalanistes'' is closely related to '' Remingtonocetus'' (the type genus ...

'', including a longer neck and fused sacral vertebral elements. This leaves ''Indocetus'' without postcranial remains, but undescribed material (as of 1998) from Kutch most likely include some that can be attributed to ''Indocetus''. Furthermore, '' Rodhocetus'', also from Sulaiman, is very similar to ''Indocetus'' and it is possible that these genera are synonyms. ''Indocetus'' is known from a partial skull, two endocasts, a right tympanic, and a right maxilla; all from the Harudi Formation. ''Indocetus'' has prominent

protocone A cusp is a pointed, projecting, or elevated feature. In animals, it is usually used to refer to raised points on the crowns of teeth. The concept is also used with regard to the leaflets of the four heart valves. The mitral valve, which has two ...

s on the molars, distinguishing it from '' Protocetus'', ''

Eocetus ''Eocetus'' is an extinct protocetid early whale known from the early late Eocene (Bartonian, ) Giushi Formation in Gebel Mokattam, (, paleocoordinates ) outside Cairo, Egypt. The specimen was first named by Fraas as ''Mesocetus schweinfurth ...

'', ''

Babiacetus ''Babiacetus'' is an extinct genus of early cetacean that lived during the late Lutetian middle Eocene of India ().. Retrieved April 2013. It was named after its type locality, the Harudi Formation in the Babia Hills (: paleocoordinates ) ...

'', and ''

Georgiacetus ''Georgiacetus'' is an extinct genus of ancient whale known from the Eocene period of the United States. Fossils are known from Georgia, Alabama, and Mississippi and protocetid fossils from the right time frame, but not yet confirmed as ''Georg ...

''. P¹ is single-rooted like '' Rodhocetus''. The tympanic bulla is more narrow than in ''Protocetus'' and ''Georgiacetus''. The endocasts included dental material, including alveoli and the bases of cheek teeth but not the crowns. P^3–4 are three-rooted and probably had protocones. The molars are smaller than the premolars and decrease from M¹ to M³. M¹ and M² have large protocone lobs.

Notes

References

* * * * * {{Taxonbar, from=Q11712114 Protocetidae Fossil taxa described in 1975 Prehistoric cetacean genera Extinct mammals of Asia