New Ammonite From An Ancient Saltwater Lake
    By Danna Staaf | January 23rd 2011 07:19 PM | 3 comments | Print | E-mail | Track Comments
    About Danna

    Cephalopods have been rocking my world since I was in grade school. I pursued them through a BA in marine biology at the University of California...

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    A new fossil cephalopod has turned up in the news! It's funny cuz I was just pondering ammonites recently.
    "It is a new species of squid, totally new, that has not been seen in other parts of the world," paleontologist Klaus Honninger told AFP. Honninger, director of the Meyer-Honninger Paleontology Museum in the northern city of Chiclayo, said the fossil was a large cephalopod of the extinct Baculite species, known for their long straight shells.
    Wait a minute--if it's a totally new species of squid, how can it be a member of an extinct species? As usual, reporting is a bit muddled. Baculites is a genus, not a species. A good analogy for genus and species (which I saw most recently in Williams' Kraken, in fact) is car make and model. Mazda is like a genus, which can contain several species, of which miata is one.

    The Examiner got things even more mixed up by confidently informing readers that:
    The multiple species of baculites include ammonites.
    Whoops! Could have caught that with some Wikipedia-based fact-checking. Baculites is actually a kind of ammonite, rather than the other way around.

    Of course, as an ammonite, the creature can't technically be called a squid. Squid and ammonites are in different subclasses of the class Cephalopoda. (Squid are Decapodiformes, while ammonites are Ammonoidea.) But I can understand the paleontologist's desire to equate his find to a modern, well-known group of animals.

    I think the coolest part of the story is this:
    "At the site, a sort of saltwater lake had formed that allowed these creatures to evolve independently," Honninger said.
    Whoa! Are we talking like Dead Sea level of isolation, or more like a Black Sea type of thing where there's still some exchange with the greater world ocean? Were there hypersaline ammonites?


    Fossil Huntress
    We find the genus Baculities on Vancouver Island. Twenty years ago, you could find dozens in a single day in the Nanaimo Group. Now the site is all but bear. Baculities were the anti-heteromorph design of the ammonites. I guess all the cool kids were twirling their shells and the Baculites wanted to be evolutionarily different. An elegant design visually, but the pumping motion of the tentacles meant that this bad boy flung himself around in the water column heading backwords -- not a great strategy for a hunter.
    Danna Staaf
    Hehe, yep, Baculites was certainly bucking the trend with its straight shell. Although as far as jetting backwards, that's actually what all the modern squid do too, and it seems to be working out for them--they're certainly very effective hunters! They have muscles around their eyes to angle them forwards or backwards, so they can probably get a decent view in either direction. It would be very interesting to know what the eyes of Baculites were like . . . That's neat about the Vancouver deposits, but a shame they're mostly gone.
    Fossil Huntress
    I picture them in the water column as tiny torpedoes. Baculites off the port side...