The elongation of the vertebrae in
Antaecetus resembles what is known from
Basilosaurus, consequently supporting the idea that their locomotion could have been similar. This would suggest that
Antaecetus swam by undulating the entire body. However, the length of the transverse processes would have restricted this movement somewhat. More specifically, the reduced space between the processes meant that the side-to-side flexibility was limited, limiting the animal to swimming through up- and downstrokes. The increase in bone density would have further impacted its lifestyle, with Gingerich and colleagues listing a variety of potential causes for such an adaptation. For instance, the corresponding increase in
ballast and lung volume would have been useful for a slow-moving animal, possibly one feeding in shallow waters close to the
ocean floor. The articulation of the ribs would also fall in line with this interpretation, as ligamentous or cartilaginous rib articulation allows for the thorax to expand during air intake while also allowing the animal to collapse the thorax at the ocean floor to minimize buoyancy. At the same time, the increased density took a further toll on the mobility of
Antaecetus, likely making it much slower to accelerate in addition to its poor maneuverability. From this Gingerich, Ayoub Amane and Zhouri hypothesize that
Antaecetus, like
Pachycetus, was a slow-moving animal inhabiting shallow coastal waters. However, its precise ecology proved to be more elusive, with its small, gracile teeth unfit to deal with either vegetation or hard-shelled prey (ruling out lifestyles akin to those of
manatees and
sea otters). Feeding directly from the ocean floor is also dismissed, as contact with sediment would lead the teeth to undergo rapid abrasion. The poor maneuverability and slow speed of
Antaecetus indicate that it was not built for pursuing prey either, leaving the possibility that
Antaecetus was an ambush hunter preying on fish and invertebrates. The remains of
Antaecetus are known from the
Aridal Formation of Morocco, where the animal coexisted with at least 5 additional early whales of different sizes.
Antaecetus was one of the larger whales of this assemblage, together with the large protocetid
Pappocetus and the basilosaurid
Eocetus schweinfurthii, which was the largest cetacean of the locality. The remaining three taxa were all smaller than
Antaecetus, including two indeterminate protocetids and the small basilosaurid
Chrysocetus fouadassaii, which in terms of size falls in between the ranges of the afforementioned protocetids. ==References==