Babiacetus is one of the larger protocetids weighing about 830 kilograms (1,830lb).[9][10] Its hydrodynamic skull and pointed, anteroposteriorly (front-back) oriented incisors are typical of archaeocetes. A densely ossified auditory bulla and large mandibular canal indicate it was adapted for hearing in water.[11]Babiacetus differs from pakicetids and ambulocetids (more primitive families) by the large mandibular foramen and a medially concave ascending ramus; distinct from remingtonocetids and basilosaurids (more derived families) by the single-cusped trigonid and talonid on the lower molars.[7] Its long synostotic (fused) mandibular symphysis, which reaches as far back as P2, distinguishes it from Pappocetus and Georgiacetus (other protocetids). Its auditory bulla is more narrow than Rodhocetus'. Babiacetus lacks the prominent molar protocone present in Indocetus.[12] The anterior premolars are large.[9]
The mandible is longer in B. indicus than in B. mishrai, and P1 is single-rooted in the former but double-rooted in the latter. The diastemata between P1 and P4 in B. indicus is absent in B. mishrai. B. indicus has larger cheek teeth and a larger M3.[12]
Palaeobiology
The teeth of Babiacetus exhibit substantial spalling, suggesting that this cetacean fed on hard-bodied prey of relatively large size.[13] To date, only cranial remains have been found, hence nothing is known of Babicetus' mode of locomotion or degree of aquatic adaptation.[11]
Gingerich, Philip D.; Arif, Muhammad; Bhatti, M. Akram; Raza, Hilal A.; Raza, S. Mahmood (1995). "Protosiren and Babiacetus (Mammalia, Sirenia and Cetacea) from the Middle Eocene Drazinda Formation, Sulaiman Range, Punjab (Pakistan)". Contributions from the Museum of Paleontology. 29 (12): 331–57. hdl:2027.42/48651. OCLC742731921.
Trivedy, A. N.; Satsangi, P. P. (1984). "A new archaeocete (whale) from the Eocene of India". Abstracts of 27th International Geological Congress, Moscow. 1: 322–23.
