Tetrapod Zoology

Scaphokogia!

Yay: day 3 of seriously frickin’ weird cetacean skull week. While we’ve previously been looking at the skulls of extant species, this time we have a fossil (or, actually, a diagram of one: from Muizon 1988). It’s Scaphokogia cochlearis from the Miocene Pisco Formation of Peru, described by Muizon (1988). Exhibiting an incredible amount of cranial asymmetry and a wide, round supracranial basin, it’s clearly a physeteroid (sperm whale), and the presence of slit-like antorbital notches, absence of nasals and other characters indicate that it’s a kogiid (Muizon 1991) (if you need help with the terminology go see the Tursiops and Kogia articles)…

i-fbb682cb520f8c0b64d194610023e750-Scaphokogia resized.jpg

Scaphokogia had a much longer rostrum than the only surviving kogiid, Kogia, and it also differed from both Kogia and Physeter in having a blunted, rectangular bony rostrum, rather than a pointed one. Exactly how this affected the shape of its head in life is a good question: Physeter has a broad-based, triangular bony rostrum, yet its massive head is deep and rectangular and wider dorsally than at the jaws. As mentioned previously, Scaphokogia is weird in having very long antorbital slits. What appear to be remnants of alveoli remain in two grooves that run along the ventral surfaces of the maxillae: teeth are unknown from the only known specimen, but Muizon (1988) suggested that non-functional teeth may have been present, but unerupted.

There are several fossil kogiids: Muizon (1988, 1991) proposed that Scaphokogia was the sister-taxon to Kogiinae, the clade that includes Kogia and its fossil relatives. Bianucci & Landini (2006) confirmed the kogiid affinities of Scaphokogia, but we await testing of the hypothesis that Scaphokogia is outside of a Kogiinae clade.

So by now you’re thinking of that huge, inescapable question that arises whenever you look at fossil whales: why the hell isn’t there a good, comprehensive volume that reviews the cetacean fossil record? And I don’t mean yet another book that looks at whale origins and archaeocete diversity, but one that covers all the fossil odontocetes and mysticetes (the Neoceti). I get asked this question quite a lot, and the best I can do is direct people to Kellogg (1928a, b). Needless to say, it’s a tad out of date now and we really need a good, modern volume on fossil whales. I’ll do it, get me the money.

More tomorrow…

Refs – -

Bianucci, G. & Landini, W. 2006. Killer sperm whale: a new basal physeteroid (Mammalia, Cetacea) from the Late Miocene of Italy. Zoological Journal of the Linnean Society 148, 103-131.

Kellogg, R. 1928a. The history of whales – their adaptation to life in the water. Quarterly Review of Biology 3, 29-76.

- . 1928b. The history of whales – their adaptation to life in the water (concluded). Quarterly Review of Biology 3, 174-208.

Muizon, C. de 1988. Les vertébrés de la Formation Pisco (Pérou). Troisième partie: des Odontocètes (Cetacea, Mammalia) du Miocène. Travaux de l’Institut Francais d’Études Andines 17, 1-244.

- 1991. A new Ziphiidae (Cetacea) from the Early Miocene of Washington State (USA) and phylogenetic analysis of the major groups of odontocetes. Bulletin du Muséum national d’Histoire naturelle (4e sér.) 12, 279-326.

Comments

  1. #1 djlactin
    July 30, 2008

    write it, and the money will come….

  2. #2 Jorge Velez-Juarbe
    July 30, 2008

    Very interesting!!! And I though that Odobenocetops was the only weird cetacean from the Pisco Formation!!

  3. #3 Darren Naish
    July 30, 2008

    write it, and the money will come….

    Err, no, I am not making that mistake ever again!

    Weird Pisco cetaceans: there are other oddballs there too, like Brachydelphis, sword-snouted Belonodelphis, a few long-beaked phocoenids, and the long-beaked, multi-toothed ziphiid Ninoziphius. The very small mysticete Piscobalaena is also odd: its rostrum looks like some sort of broad-bladed sword.

    ['Roman broadsword' now deleted, goddammit!!]

  4. #4 Thomas R. Holtz, Jr.
    July 30, 2008

    Is it just me, or do other people think this looks like an anterior (or posterior) view of a strange sauropod vertebra?

  5. #5 Daniella Perea
    July 30, 2008

    Maybe should recycle it for SV-POW!

  6. #6 Sordes
    July 30, 2008

    Wow, again another fossil kogiid, I really love those archaic guys of the sperm whale family (although I prefer the great killer sperm whales).
    BTW, perhaps I know an extremely strange fossil porpoise which even you don´t know, because it is still not officially described, but only exhibited in the NHM of San Diego. Or do you know what oddball I mean?

  7. #7 Darren Naish
    July 30, 2008

    Sordes writes…

    BTW, perhaps I know an extremely strange fossil porpoise which even you don´t know, because it is still not officially described, but only exhibited in the NHM of San Diego. Or do you know what oddball I mean?

    Rachel Racicot and colleagues have been working on a bizarre new phocoenid from the San Diego Formation in which the lower jaws are much longer than the rostrum, and have a long, fused, toothless symphyseal region. I don’t think it’s published yet. Is this the taxon you have in mind?

  8. #8 johannes
    July 30, 2008

    > its rostrum looks like a Roman broadsword.

    Like a claymore or a schiavona – these are the weapons usually referred to as broadswords? Single edged, assymetrical and with a basket hilt? This would be a strange cetacean, indeed:-0! Assymetry, of course, is quite common in cetacean skulls, but an assymetrical rostrum?

    This said, it’s hard to imagine that the Romans actually used such weapons, wich are only known from renaissance and later times. Of course, the schiavona – as it’s name, meaning “the Slavic one” in Italian, suggests – originated on the Balkan peninsula, and the very last Byzantines might have used it, but it needs a wide stretch of imagination to call them Romans.

    Perhaps the rostrum had the shape of a gladius. This would still look unusual, but more convincing.

  9. #9 Sordes
    July 30, 2008

    Yes Darren, that?s exactly the guy I mean, once again you did get me. Is there something about any living or extinct tetrapod you don?t know? When I saw the photo of the skull for the first time I had one of the WTF!?-moments you sometimes get if you discover something you had never expected. It reminds me a lot of the Saurodon-species from the late Cretaceous. You can also find a nice photo of the skull at flickr if you search for “bizarre porpoise skull”. I turned even out that I know one of the guys who examined it since a long time from a forum.
    I think this fossil is especially interesting, because it is “just” a porpoise, given the fact that those small whales are among the most unspectacular of all living whale species. I think there is still a whole lot to discover about fossil whales, for example one of my personal favourite, the hypothetical proto-narwhale Furcadon. I know there are also some other extremly strange but still not published freaks out there, as well as very interesting new dates about already known fossil species.
    I have already thought about the idea to make some kind of book about the extinct whales, at least the more spectacular ones, as well as the other cool marine beasts of the last 65 Million years, like sabertoothed planctivorous giant salmons and four-tusked pseudo-walruses.
    But this would need a lot of time, and I have to finish my actual project at first. It is really a shame that there is nearly no literature about this. The best one you can find is possibly “Neptune?s Ark”.

  10. #10 Sordes
    July 30, 2008

    The term “broad-sword” is very popular, especially in fantasy role-playing games and literature, but in the actual terminology about blade-weapons you won´t found it only rarely. The most common type of sword used by the early romans was the gladius like Johannes already wrote. Most of them had straight edges, but some forms had actually a more willow-lead form, what would come close to the skull of Piscobalaena nana. The later roman swords of the spatha type were already very similar to the typical sword form, but differed mainly in the hilt and cross-guard from later types.

  11. #11 Darren Naish
    July 30, 2008

    Ladies and gentlemen, I give you… the chinny-chin-chin porpoise. Hmm, should have nicked it for Tet Zoo! An abstract about it was published in Journal of Vertebrate Paleontology 27, suppl. 3…

    Racicot, R., Deméré, T. & Rowe, T. 2007. Morphology of a bizarre new fossil porpoise (Cetacea: Phocoenidae) from the Pliocene San Diego Formation of southern California, USA. Journal of Vertebrate Paleontology 27 (supp. 3), 132.

    They report that it’s perhaps the sister-taxon to Piscolithax. It’s been CT-scanned.

  12. #12 Sordes
    July 30, 2008

    BTW, the insider-name of this guy was “skimmer-porpoise”.

  13. #13 Dr Vector
    July 30, 2008

    BTW, the insider-name of this guy was “skimmer-porpoise”.

    Damn, if you want to make a joke around here, you have to move fast.

    Thanks for the link to the chinny-chin-chin porpoise. One commenter on that photo wrote:

    I knew of some really really strange prehistoric marine mammals like the six-tusked walrus Gomphotaria or the bizarre marine giant sloths of Peru. But I have never ever heard about this freak.

    I knew about the marine sloths, and you’ve blogged about them before, but I did not know that Gomphotaria existed. I nominate Weird-Ass Walruses for your next theme week. Or theme day, if there aren’t enough of them. Whatever, I just want to learn more about Gomphotaria.

  14. #14 Sordes
    July 30, 2008

    Matt, this commenter was actually me…
    The walrus family was once much more diverse than today, and there were a whole lot of extremely strange forms, enought to make a whole “week of strange prehistoric walruses”. Gomphotaria pugnax was not really a true walrus, but it was strange anyway. There were animals like Aivukus with short tusks or Imagotaria.
    It is very interesting that there was a species named Valenictus chulavistensis which was even higher specialized than modern walrusses. It had long tusks but completely lacked other teeth.
    My personal favourite is Pelagiarctos thomasi, which was possible some kind of vertebrate-hunting hypercarnivore which haunted the colonies of other seals.
    BTW, the skimmer-porpoise was no joke (my english is too bad to make jokes), my acquaintance from the San Diego NHM actually told me that they called it so.

  15. #15 Nathan Myers
    July 30, 2008

    I confess I can’t tell how many jokes there are in the last four comments.

  16. #16 Max Paddington
    July 30, 2008

    I would like to cast my vote for a ‘walrus week’ too. I’ve been curious about the strange and unusual fossil walruses for a while now.

  17. #17 Boesse
    July 30, 2008

    Few things:

    I’ll be working with Ms. Racicot myself on some additional fossils of the same bizarre undescribed skimmer porpoise I collected from Northern California. The lower jaw is not the only weird feature; it also has extremely large, bulb-shaped premaxillary eminences, and wear facets on the lateral margins of its teeth. Rachel calls it the skimmer porpoise as well. Folks in the LACM have referred to it as the half-beaked porpoise.

    Darren, if you think Piscobalaena is weird, Herpetocetus (sister genus to P. nana) is even weirder. It could only open its lower jaw to about 20-30 degrees or so (ballpark), and had a much stranger auditory system (and a similarly shaped rostrum). You can hear all about it at my talk at 2pm on saturday at SVP in Cleveland…

    As for walruses (another group dear to my heart): Gomphotaria is pretty damn strange. It had four tusks, not six, though (it isnt THAT weird…). The lower tusks were closely appressed, and when the mouth was closed, were between the upper tusks (which splay slightly laterally). The tusks are also abraded to stublike ends, presumably from substrate interaction.

    Its sister genus, Dusignathus, had “tusks” as well; male D. santacruzensis had 7″ canines, but only 1.5″ or so actually erupted; god knows why such a long root was necessary for such a short crown. Dusignathus also has really short, extremely robust forelimbs (perhaps the most robust forelimb elements of any odobenid, or pinniped for that matter). And Darren, if you ever do weird walrus week… I’ve done plenty of cranial reconstructions for these guys.

  18. #18 Darren Naish
    July 30, 2008

    Wow wow wow… you collected the half-beak porpoise? Dumb question: what is your real name Boesse? Whatever, I am truly honoured to have you here as a visitor (and the rest of you, of course).

  19. #19 Boesse
    July 30, 2008

    Hahaha, no, I didn’t collect the San Diego Fm. material – the best specimen is a fairly good skeleton, with skull and jaws, etc. That was collected by SDNHM personnel.

    I should have been more specific – what I tried (and, er, failed) to say that I collected some additional material of the same taxon from northern California (the Purisima Fm.), the best of which is a nearly complete skull (and it is juvenile, unlike the only other known skull). Sorry for the confusion! Oops…

    In other words, please don’t be honored! (or honoured??) This taxon is Rachel’s baby, and it is up to her when we’re going to describe the Northern CA material. She’s the one who deserves the glory, not me. Oh, and I’m Robert Boessenecker.

  20. #20 Sordes
    July 31, 2008

    This is really great to hear Robert. I had my information about the skimmer-porpoise from Morgan Churchill whom I know since several years from a forum. I´ve been interested in the prehistoric marine mammals since a longer time, as they are really highly fascinating, but you can hardly find something about them. They are always in the shadows of Ichthyosaurs and other reptiles, only some exceptions like Basilosuaurs are more popular. Even the fossil pinipeds have some highly bizarre members which nearly never get any attention.
    Untill Morgan sent me the paper about Gomphotaria I had no idea how it actually looked and knew only the (comparably ugly) picture from Wikipedia which actually shows it with six tusks. I actually thought about a life-reconstruction of this creature, or at least the half-beaked-porpoise for my collection. when I saw the skull I was also a bit irritated about the strange bulbs on its head. There is also this “robust” porpoise skull in the San Diege exhibition, is there anything more known about it?

    For Darren: What do you think, what´s about making an own blog post about the skimmer-porpose, it is really to bad to rest in the comment-section I think. And a prehistoric walrus-week would be really great too.

  21. #21 Darren Naish
    July 31, 2008

    Thanks for comments. I’m trying to get permission to use images of the half-beak porpoise, so stay tuned. Ahh, Robert Boessenecker.. you’re one of Dave Varricchio’s? Say hi to Dave for me.

    I’ve long thought about doing walruses, if you’ll pardon the expression, as (back when I did some work on pinnipeds)I played a lot with extant walrus skulls and would like to share their awesomeness. I’ve been corresponding with Paul Brodie and he recently sent me some neat stuff on walrus skin anatomy and other such stuff. I will talk with Robert behind the scenes and see where we can go with this. Incidentally, I once corresponded with Larry Barnes about dusignathines (the group that includes Gomphotaria) and was going to be including Gomphotaria in yet another of those failed book projects (it was going to be called ‘Extreme Evolution’). I think Dr Barnes is attending this year’s SVPCA, in which case I should get to meet him.

  22. #22 Richard Hing
    July 31, 2008

    “sabertoothed planctivorous giant salmons”

    OK, I know it’s not a tetrapod, but this has got me intrigued.

  23. #23 Sordes
    July 31, 2008

    I was talkin about Oncorhynchus rastrosus, or Smilodonichthys rastrosus (what sounds much better). It was a giant salmon which could reach a length of 3m. It had very strange teeth which were possibly used at mating, as they don´t look like piercing instruments to catch prey, but more a bit like the hook-shaped mouths of some male salmons. But the other teeth and the rest of the mouth indicate that they were no true hunters, more more planctivorous. They are known from marine and freshwater deposits, i.e. they mainly lived in the sea but spawned in the freshwater like many living anadromous salmons.

  24. #24 Richard Hing
    July 31, 2008

    Thanks for that info.

    Why are there so many cool animals known from the Pacific compared to the Indian and Atlantic Oceans, I wonder?

  25. #25 Darren Naish
    July 31, 2008

    Why are there so many cool animals known from the Pacific compared to the Indian and Atlantic Oceans, I wonder?

    An answer was proposed by Geerat Vermeij in his 1987 Evolution and Escalation. It’s essentially to do with the Pacific province having a far more tumultuous, complicated history where there are more niches and (apparently) an awful lot more complicated variations in the armour and shells of invertebrates.

  26. #26 DDeden
    July 31, 2008

    Teh Cooliest blog! Tet Zoo! Tet Zoo!

    Yes, wierd walruses and creepy cetaceans and saber tooth salmonids too!

  27. #27 Boesse
    August 2, 2008

    Sordes: I’m pretty good friends with Morgan too (Hi Morgan!). He’s gone from studying balaenid mysticetes to pinnipeds.
    About the broad headed porpoise also in the exhibit: its missing the top of the skull, but based on what’s preserved, I would place it much closer to extant phocoenids, and probably within the Phocoeninae (unlike the skimmer porpoise). It also has very weird ears (periotics), which show some odd features, but also suggest it is closer to extant porpoises.

    Darren: I will certainly tell Dave you said hello; I’ll be back at MSU in a month or so. Some articles on weird pinnipeds would be awesome – I’ll email you in a couple days about that stuff.

    And about the skimmer/halfbeak porpoise, I’d suggest contacting Ms. Racicot, since she’s the researcher studying the taxon.

  28. #28 Sordes
    August 2, 2008

    Robert: Thank you very much for the information about the broad-headed porpoise. Even if it is by far not as strange as the skimmer porpoise it is still very interesting. It is again and again amazing to see what diversity many genera once had, even some of those with only a single surviving species like the whalerus or which are in general comparably boring (okay, no animal is really boring, sometimes even those who seems to be very boring at first can be really interesting, pigeons for example, but I think you know what I mean).

  29. #29 DunkTheBiscuit
    August 2, 2008

    All these fascinating creatures you never find out about as a layperson… Thanks for taking the time to write so accessibly about them. You’re one of my daily stopoff blogs.

    I seem to remember a reconstruction of a porpoise in a National Geographic magazine several years ago that looked like someone had grafted a walrus head onto a porpoise body. What the heck was that? Can I find out any more about it, because the idea has intrigued me ever since.

  30. #30 Sordes
    August 2, 2008

    This was surely Odobenocetops, an extremely bizarre whale. But it was no porpoise but probably closer related to living narwhales. Just google for it.

  31. #31 DunkTheBiscuit
    August 2, 2008

    Thankyou for taking the time to reply, Sordes. Difficult to Google on just a description, a name makes things much easier to find.

  32. #32 Mike from Ottawa
    August 3, 2008

    Once again I’m ambushed by Darren and the excellent commenters here. Looks like a short post, then wham! tons of weird and wonderful animals I’d never heard of and I’m googling all over the place. Hours pass. Whew! and Wow!

    Thanks, Darren and thanks to the commenters here.

  33. #33 David Marjanovi?
    August 11, 2008

    all the fossil odontocetes and mysticetes (the Neoceti)

    What happened to Autoceta?

    Is it just me, or do other people think this looks like an anterior (or posterior) view of a strange sauropod vertebra?

    Seconded.

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