“…Derived protocetids showed progressive modification of the sacrals: both their articulations with the pelvis and with each other were lost (Bebej et al, 2012;Gingerich, Raza, Arif, & Zhou, 1994;Hulbert et al, 1998;Uhen, 2014). Derived protocetids lacked the sacral series completely, but their lumbar counts were enhanced by four, strongly suggesting that four dedifferentiated sacral homologs were present at the posterior end of the lumbar series (Buchholtz, 2007;Uhen, 2014). Derived protocetids lacked the sacral series completely, but their lumbar counts were enhanced by four, strongly suggesting that four dedifferentiated sacral homologs were present at the posterior end of the lumbar series (Buchholtz, 2007;Uhen, 2014).…”