Vertebra 31



Vertebra 31 in anterior view.

I now have a copy of Whales of the World by Spencer Wilkie Tinker, published in 1988 from which the following information is mostly derived.  Vertebra 31 is one of the caudal (tail) vertebra - the last of them that I have.  This is it in anterior view with the two facets (flattened bits) for the attachment of the chevron bones visible at the bottom.  Caudal vertebrae are identifiable as such by the presence of these paired facets.  The lumbar (back) vertebrae have a single "inferior carina" (or ridge) which widens towards the posterior (tail end) of the last one (more on these later).  I have 7 caudal vertebrae in total, one could expect 28 or 29 of these in a Long-finned Pilot Whale so I am few short.  The whale with the fewest caudal vertebrae seems to be the Pigmy Right Whale (Capera marginata) which has about 15 and that with the most is the La Plata River Dolphin (Phocoenoides dalli) which has about 48.