Help With a Whale Fossil

[Harry Pristis]

I don't know much about whale fossils . . . Can I get some help?

This appears to be an auditory bulla which seems unlike the larger specimens from baleen whales.  I think it may be a damaged bulla from Pomatodelphis.  Any thoughts?

 

In the one view, I've marked with a yellow ''x" two pholadid clam borings so that they don't distract.  That same view seems to show an area of shear which represents a missing process.

[Shellseeker]

Harry,  Very Interesting. In 8 years of intensive hunting, in and around DeSoto county, I have found whale and dolphin bulla, but have never seen anything like this one.  

[doushantuo]

from my own library(short on cetacean otology):

great piece by JG from JVP:

 

GLuherp(1996)JP.pdf

[Al Dente]

I'm sure Bobby will be able to give you the correct identification. Seems too big to be a toothed whale bulla. It must be one of the small baleen whales, maybe a Cetothere.

[Boesse]

Hey Harry - this specimen is likely to be a true cetotheriid, like Herpetocetus. The bulla of Pomatodelphis is about 1/3 the size of your specimen. Herpetocetus is relatively common from the Lee Creek Mine and is the smallest baleen whale known from the Pliocene - and the last true "dwarf" mysticete. Here's a bulla which Kellogg (1944) reported from Florida and called "?Mesocetus" (a name no longer in use), and which  Bouetel and Muizon (2006) referred to the Peruvian whale Piscobalaena, but probably actually represents Herpetocetus transatlanticus or something similar. There is a second unnamed herpetocetine from the early Pliocene of the southeastern USA that has similar earbones.

[Harry Pristis]

Doushantuo . . . Thank you for the 'otology' paper.  Alas!  I am not prepared for the technical details -- I immediately slipped into a state of information overload.

 

Bobby . . . Thank you for an excellent analysis!  With illustration!  It doesn't get any better.  A dwarf mysticete, Aff. Herpetocetus transatlanticus.  I am surprised and pleased.

 

Maybe I am wrong to label both of these cervical vertebrae as odontocetes.  The larger example seems to be from a relatively large whale.  Is there anything diagnostic about these bones?

[Boesse]

Hey Harry, no worries - always happy to help with fossil cetaceans. As for the vertebrae, the big one is likely a medium sized baleen whale, perhaps something the size of a modern minke whale - it is possible that this could be a large odontocete. Judging from the taxa listed in Morgan (1994) from the Palmetto Local Fauna of the Bone Valley Fm., several medium-large odontocetes are present, including Kogiopsis floridana, Physeterula sp., Mesoplodon sp., and Ninoziphius platyrostris (possibly misidentified according to a recent paper). If it were any larger, the larger vertebra would be certifiably mysticete, but it's at this problematic size range shared by multiple small baleen whales and large odontocetes. The smaller vertebra is almost certainly from an odontocete.

 

From all of this inconclusive arm waving, you probably get the idea that isolated vertebrae are not terribly diagnostic. Unless it's a partial skull, mandible, or an earbone, cetacean remains are sadly not very diagnostic. On occasion there are critters with useful postcrania (e.g. Basilosaurus) or useful teeth (toothed mysticetes, stem Odontoceti, archaeocetes).

[Shellseeker]

Just adding another medium sized whale cervical vertebrae found November , 2018.