Remingtonocetids have long and narrow skulls with the external nare openings located on the front of the skull. Their frontal shields are narrow and their orbits small. Their mouth has a convex palate and an incompletely fused mandibular symphysis. The dental formula is 3.1.4.33.1.4.3. The anterior teeth are flattened mediolaterally, making them appear shark-like.[3]
Cranial fossils are common but dental remains are rare. The postcrania morphology is based entirely on a single specimen of Kutchicetus which was small and had a long and muscular back and tail. Perhaps remintonocetids swam like the South American giant otter which swims with its long flat tail.[4]
With long and low bodies, relatively short limbs, their elongated rostrum, remingtonocetids looked like mammalian crocodiles, more so than Ambulocetus. They could both walk on land and swim in the water and most likely lived in a near-shore habitat. At least one genus, Dalanistes, had a marine diet.[2]
Remingtonocetids are often found in association with catfish and crocodilians, as well as protocetid whales and sirenians. They were probably independent of freshwater.[4]
Distribution
Remingtonocetidae was long considered endemic to the northern coastline of the ancient Tethys Ocean (in present day Pakistan and India) during the Eocene, but the discovery of Rayanistes in Egypt indicates that remingtonocetids had a broader distribution than previously thought.[2] A single tooth recovered from the Castle Hayne Limestone of North Carolina, USA closely resembles that of remingtonocetids; if it belongs to one, it indicates that they may have been found as far west as eastern North America, expanding their distribution across the Atlantic.[5]
^Ryan M. Bebej, Iyad S. Zalmout, Ahmed A. Abed El-Aziz, Mohammed Sameh M. Antar and Philip D. Gingerich (2016). "First remingtonocetid archaeocete (Mammalia, Cetacea) from the middle Eocene of Egypt with implications for biogeography and locomotion in early cetacean evolution". Journal of Paleontology. in press. doi:10.1017/jpa.2015.57.
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