Rodhocetus commits to the water
The pelvis loosens from the spine, the tail takes over propulsion, and the whale stops coming ashore.
- When
- —
- Duration
- 1 million years
- Known to
- ± 1 million years
- Era
- Eocene, Cenozoic
Rodhocetus and its relatives, found in offshore marine shales rather than river deposits, mark the point where the transition passes the halfway line. The sacrum is no longer fused to the pelvis, which frees the spine to flex vertically for tail-driven swimming but makes supporting the body on land nearly impossible. It is also the point where the group leaves the Indo-Pakistani coast and begins to spread: the later archaeocetes are found on both sides of the Atlantic and the Pacific.