Figure 14. Head versus tail presentation of near- and full-term calves in a domestic cow and harbor porpoise.

Domestic cow (Bos taurus) calf (blue) in (A) ninth and final month of gestation before ‘turning’ (axially rotating), (B) turned as the birth process begins, and (C) with forelimbs and head partially extruded in the initial stage of birth (from [51], [52]). Harbor porpoise (Phocaena phocaena) (D) with full-term calf (blue) with tail partially extruded in the initial stage of birth (from [18]).