Mark D. Uhen
Dorudon atrox is a medium-sized archaeocete cetacean, around five meters in length from snout to tail in life, and is known from the Birket Qarun and Gehannam Formations of Fayum, Egypt. These formations are primarily Bartonian, but probably straddle the Bartonian-Priabonian boundary. The Bartonian is the last European marine stage in the middle Eocene, while the Priabonian is the first marine stage in the late Eocene, and the formations from which D. atrox are recovered are around 41 to 40 million years old. Anatomical features found in D. atrox and its close relatives (Family Basilosauridae), indicate that these animals were the first fully aquatic cetaceans. (Go to the link and see more of this paper.)
Publisher: University of Michigan
Year of Publication: 2003
Location: Ann Arbor, MI
Volume Number: 34
# of Pages: 222