New species of protocetid archaeocete whale, Eocetus Wardii (Mammalia: Cetacea) from the Middle Eocene of North Carolina

Journal of Paleontology, May 1999 by Uhen, M D

Occurrence.-Protocetines are known from Indo-Pakistan, Egypt, west Africa, and eastern North America and range from late early Lutetian to early Bartonian in age. Indocetines are known only from the Lutetian of Indo-Pakistan (Sahni and Mishra, 1975; Gingerich et al., 1995).

Discussion.-Thewissen et al. (1996) recently separated the Protocetidae of earlier workers into four separate families. They placed the earliest cetaceans in a separate family, Pakicetidae, recognized a new family, the Ambulocetidae, and affirmed the separate status of the previously described Remingtonocetidae (Kumar and Sahni, 1986). The remaining taxa were retained in the family Protocetidae. This arrangement is followed here.

Protocetids are the earliest group of cetaceans that are found outside of Indo-Pakistan, reaching across Africa to the western Atlantic. Georgiacetus, which has a large innominate, Natchitochia, which has a large single sacral vertebra (and presumably an innominate as well), and Eocetus, which has a well-developed innominate (as described here), all demonstrate that the protocetids dispersed widely prior to their adoption of the fully aquatic existence seen in basilosaurid archaeocetes (Uhen, 1998b).

Subfamily PROTOCETINAE Stromer, 1908

Type genus.-Protocetus Fraas, 1904.

Diagnosis.-Members of the subfamily Protocetinae have either a single sacral vertebra connected to the innominata or they have no sacral vertebrae that are directly connected to the innominata or connected to one another. The subfamily Protocetinae is most likely paraphyletic, giving rise to the Basilosauridae (Thewissen et al., 1996; see below).

Included genera.-Eocetus Fraas, 1904; Pappocetus Andrews, 1920; Babiacetus Trivedy and Satsangi, 1984; Takracetus Gingerich, Arif, and Clyde, 1995; Gaviacetus Gingerich, Arif, and Clyde, 1995; Georgiacetus Hulbert et al., 1998, Natchitochia Uhen, 1998.

Occurrence.-Old World protocetines are known from IndoPakistan and Africa. Gaviacetus, and Takracetus are known from the Domanda Formation of Pakistan, which is early Lutetian in age (Gingerich, et al., 1995). Babiacetus is known from Drazinda Formation of Pakistan and the "gypseous shale bed of Babia Hills", India (Trivedy and Satsangi, 1984), both of which are late Lutetian in age (Gingerich et al., 1995).

The location of the holotype specimen of Eocetus schweinfurthi was described by Fraas (1904a, 1904b) with E. Stromer. Gingerich (1992) interpreted their description to represent the Giushi Formation, which is Bartonian in age. Fraas (1904a) also described Protocetus atavus from Gebel Mokattam. The position of the holotype locality and the determination of which formation produced P. atavus was also discussed in detail by Gingerich (1992), who concluded that the holotype of P. atavus is from the Lower Building Stone Member of the Mokattam Formation, of middle Lutetian in age. Pappocetus lugardi was described by Andrews (1920) from the middle Eocene Ameki Formation of Nigeria (Halstead and Middleton, 1974).