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February 18, 2012
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We all love identifying – or, trying to identify – weird carcasses. Back in December 2011, marine biologist and world chiton expert Douglas Eernisse of the University of California (Santa Cruz) sent me the series of photos you see here and below. They show a smallish cetacean (total length about 3 m), found beached and in partly decomposed condition at Loreto, Baja California. A large damaged region on the animal’s tailstock seemed to demonstrate death by collision with a boat.
The people who discovered the carcass identified it as a Pygmy sperm whale Kogia breviceps and noted that it possessed the asymmetrical blowhole typical for sperm whales. Hmm.. oh really?
Douglas and I have been discussing the carcass in an effort to identify it, but in the interests of sharing the fun, I have Doug’s permission to post the images here. Check out the many anatomical details you can see in the photos and see if you can pin down the carcass’s precise identity. To the winner – the spoils!
Thanks again to Douglas Eernisse for the photos. For previous Tet Zoo articles on weird marine mammal carcasses, see…
About the Author: Darren Naish is a science writer, technical editor and palaeozoologist (affiliated with the University of Southampton, UK). He mostly works on Cretaceous dinosaurs and pterosaurs but has an avid interest in all things tetrapod. His publications can be downloaded at darrennaish.wordpress.com. He has been blogging at Tetrapod Zoology since 2006. Check out the Tet Zoo podcast at tetzoo.com!
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False killer whale (Pseudorca crassidens)?
Link to thisPilot whale (Globicephala)? Dunno if short or long finned.
Link to thisnoted that it possessed the asymmetrical blowhole typical for sperm whales. Hmm.. oh really?
Yeah… Kogia has a fairly normal odontocete blowhole which is skewed slightly to the left whereas Physeter has that “s”-shaped madness on the far left end of its head. I can’t clearly see any blowhole on this carcass.
It appears that this carcass lacks the prow-like head shape (and subsequent underbite) of Kogia and the tooth shape is totally different. Where the heck are all the teeth anyways?
Link to thisOh wait, Grampus griseus reaches over 3 m, has a very large dorsal fin placed about halfway down the body, and most importantly, only has a few pairs of teeth placed toward the anterior end of the mandible. I’m going with Risso’s.
Link to thisIt only has 2 pairs of teeth in the lower jaw. That would suggest a member of the Ziphiidae, male. Probably a young male, since it seems to be small.
Link to thisBut the lack of prominent beak could mean I’m wrong
I’m going to go with Grampus griseus, it doesn’t seem to have the telltale notch in the forehead, but the teeth and the square shaped head say Grampus to me.
Link to thisIt’s a demonoid.
Good thing it died before it got to Sandy Eggo. Might’ve et the whole town.
Link to thisGrampus would be the most likely species there; the teeth and the head shape fit.
Link to thisCan’t be Kogia – it doesn’t have nearly enough teeth in the lower jaw. I agree with Grampus griseus. It’s not easy to see the groove in the center of the forehead but there’s definitely an indentation there in the topmost photo; hard to tell how much the shape changed with partial decomposition and dessication.
Link to thisMarine gorgonopsian.
Link to thisIt’s actually a highly decomposed raccoon/sloth/opossum/cat. Or an aquatic ropen.
In all seriousness, Risso’s dolphin sounds like the most plausible candidate to me.
Link to thisCameron:
“only has a few pairs of teeth placed toward the anterior end of the mandible”
Yeah, the teeth are diagnostic; that can really only be a Risso’s dolphin Grampus griseus.
Link to thisFin Whale, For a brief moment i was sure it was Gov Christie of New Jersey, he`s always beaching himself, a whale of a guy.
Link to thisI’d go with Risso’s dolphin due to the small number of robust conical teeth at the front of the lower jaw. The forehead looks slightly concave, which could be the vestiges of the diagnostic crease. It looks like some scavenger has deliberately targetted the “fat window” in the lower jaw.
Link to thisA vote for Risso’s dolphin, but I’m a pinniped what do I know.
Link to this