Friday, January 30, 2009

Time for a quiz


In between grant writing fury, I thought I'd take a moment to post a picture of a very odd fossil, and see if anyone could correctly identify it.

Some hints: this is from my field area, so it is marine, from central California, and approximately 6 million years old, and it belongs to a vertebrate. Also, it is very incomplete, but there are several features that distinguish it. So - now it is your job (if you so wish) to figure out what it is. And yes, '20 questions' is okay-ish.

Only one rule: folks who have already seen this can't give it away.

Good Luck!
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5 comments:

  1. AnonymousJanuary 30, 2009 at 12:31 PM

    I know what it is!

    ReplyDelete
  2. J. Velez-JuarbeJanuary 31, 2009 at 6:37 AM

    Interesting!! I've got a some of questions.

    Is this from a marine tetrapod?

    Is this from a terrestrial tetrapod?

    Is the picture on the left a lateral view?

    ReplyDelete
  3. Robert BoesseneckerJanuary 31, 2009 at 2:30 PM

    Good questions:

    1- no

    2- also no

    3- no, but the middle picture is

    Hope this doesn't make this any more difficult!

    ReplyDelete
  4. J. Velez-JuarbeFebruary 2, 2009 at 8:38 AM

    Thanks for the answers, I'll give it a try then.

    Elasmobranchii - fragment of the articular surface of a vertebra.

    ReplyDelete
  5. Robert BoesseneckerFebruary 2, 2009 at 1:04 PM

    Good job! Yes, it is a partial centrum of a large elasmobranch. In the case of the Purisima Formation, Carcharocles was already extinct by this point, and Carcharodon is not large enough to produce a 15cm wide vertebra; however, Cetorhinus maximus is extremely common in this deposit (and this bed in particular), and it likely belongs to Cetorhinus (otherwise known as a basking shark for all you non-shark folks out there).

    ReplyDelete