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Friday, March 10, 2017

Conodonts or "Cono-dos:" Odd Index Fossil Elements Belonged to Extinct Eel-Like Animals

      Conodont elements are microfossils made of phosphate or apatite; they are some of the planet's most useful index fossils. {Index fossils are those found in a narrow time range and wide spatial distribution that are used in the identification of related geologic formations.}





     Conodonts (Greek kōnos, "cone", + odont, "tooth") are extinct agnathan chordates resembling eels, classified in the class Conodonta. 




      For several decades, conodonts were known only from odd, wildly and disparately shaped, tooth-like microfossil assemblages found in isolation; these microfossils are now called conodont elements.





     However,  texts published before the early 1980's refer to the teeth-like assemblages as the actual conodonts (see below).
      

        The conodont animal's soft parts were finally discovered in a lagerstätte (fossil bed of extraordinary preservation) in the Bear Gulch Limestone in Montana.



     The discovery led to the eventual recreation of what these agnathan chordates, who lived mostly during the Paleozoic, looked like.





       The conodont elements are widely used not only to define a time period of deposition but also as paleothermometers which record the degree to which sediments have been "cooked." This characteristic is quite useful to oil and gas paleontologists.
            

     The conodont elements may readily be removed from their calcium carbonate sediments by using a mild acid to dissolve the CaCO3, leaving a suite of conodont elements. My micropaleontology project at the U. of Arizona yielded a conodont suite using this method of dissolution.



        How suite it is! Though, I must say, the conodont assemblages were rather a wonderful mystery until recently. . .



          The Conodonta creatures did not have jaws but had these odd assemblages at the "mouth" ends of their bodies.


      By the way, the inspiration for this week's post was, oddly enough, limestone outcrops at the Tsingy Nature Reserve in Madagascar that we discussed last week. (All about scale, once again. . .).

Have you encountered conodont elements before? Do you have any Conodon'ts or Cono-dos? ;-)
Steph

☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆

Bonus images: Conodont elements on the head of a nail in a Scanning Electron Microscope (SEM) image:





And, with a bit of gold:


Happy pi day!


38 comments:

  1. You may read more about these enigmatic fossil elements here.

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  2. Replies
    1. Thanks, jan. That was the best comment to wake up to on SAT SATurday. {I believe I'm having a wee bit of test anxiety by proxy; the kids will do great.}

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  3. Talia was the daughter of friends of friends.

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    1. I know. I wish the medical team in Seattle had listened to Talia and to her father.

      My son's godparents had a similar experience with a PCP who dismissed their daughter's knee pain due to her young age and relative good health. She was prescribed steroids when she actually had a bacterial infection. She returned to the doctor, but he dismissed her once again. By the time she went to the hospital, the infection had spread throughout her body. She died, at 26, in a US hospital, of a bacterial infection that antibiotics would have cured.

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    2. Coincidentally, I just caught a snippet of this Freakonomics episode on medical errors in the car just now. (It's not the latest one, BTW; I guess WNYC was just rebroadcasting it.) I haven't heard the whole piece, but it sounds relevant to your stories.

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    3. Medical errors happen, sadly. That's why I would ask so many questions when my kids needed medical care. Once, it saved Zoë from getting 10x the dosage prescribed.

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  4. Replies
    1. No, but I did a fair amount of reading about the health effects of EMF about 20-25 years ago. Not much evidence for any real risk, as long as you're not standing right in front of a high-power microwave horn or radar antenna.

      Did I ever mention my 5 minutes of fame on Eye-to-Eye with Connie Chung, talking about electromagnetic interference with medical devices?

      (BTW, your Electronic Silent Spring link above points back to this blog post. I assume you meant to link to Katie Singer's site.)

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    2. No, I don't think so, jan. Do you have a vdeo clip of your 5 minutes of fame?

      Thanks for the corrected link, also.

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    3. I have a VHS tape recorded off the air somewhere around here. Not sure how to get it in Internet-usable form.

      This was back in the early-ish 90s, when you started seeing signs in hospitals warning about using cell phones, and when we got our first automatic external defibrillators on our ambulance squad. I wondered about how the 2-way radios we and the police use would affect the defibs. Would a defib still be able to recognize a shockable cardiac rhythm if one of us tried to use a radio during CPR (which happens commonly). So I hooked up a defib to a test unit that produces a variety of simulated cardiac waveforms and keyed the mic switch on my walkie-talkie while the defib was analyzing. And, as I'd guessed, the unit failed to recognize V-fib. I.e., if it had been a real patient in cardiac arrest with a treatable arrhythmia, we would've missed the opportunity for a save.

      I posted my little experiment on a newsgroup I'd participated in. Some time later, I got a call from a producer for Eye-to-Eye who was putting together a segment on the topic and got my name from a researcher in the field who'd seen my post. She came down to our squad building and had me re-create the demo on tape. (Amazingly, it worked the same way while being recorded.) The segment aired on December 1, 1994.

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  5. The amount of time you spend at this company's website might indicate where you are on the Asperger's spectrum, but I think it's cool, anyway.

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  6. This seems like just the group to enjoy writing equations. There are prizes!

    Example: Einstein's A = x + y +
    z where:

    A = success in life
    x = work
    y = play
    z = keeping your mouth shut

    ================================

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  7. I am excited to be going to an NPR taping of "Colorado Matters" with Scott Carney on "What Doesn't Kill Us. . ."

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  8. The Smith-Berkeley connection. Carol Crist is an inspired choice.

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  9. I think i'll move to Bear Gulch, Montana! Sounds like there may be some cowpokes there.

    Those conodont assemblages look more like combodont assemblages to be.

    LegoSaysThatInBearGulchWeCombOurHairWithAWagonWheel

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    1. ...to ME!

      LegoWhoWoulfStillBeAliveHadHeBrushedHisAchillesTeethRegularlyWithPedsodent!

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  10. Lego, died of the toothache in his heel?!

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  11. Happy pi day! {See new image added above.}

    Happy pie-making northeasteners, jan, Joanne and Paul. Perfect day for it!

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    1. The hard part is going to be shoveling out. Spoiled my apatite. (Not condoning more fossil puns, mind you.)

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    2. jan, how much snow do you have in NJ?

      Other reports from Blizzard Land?

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    3. Send some west, please. We have had 0 snow in all of March, typically our snowiest month.

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    4. You're welcome to all you can haul away. I wish you'd asked yesterday; I could've saved myself a lot of work.

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    5. It's also Photoshopped.

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  12. I think someone at The New York Times must be a PEOTS reader. Links on its home page this afternoon point to a volcanic eruption, Throggs Neck, and our official mascot!

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    Replies
    1. There must be a causal relationship! {Or a casual one, at least. . .}

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  13. Replies
    1. Me, too!

      84 degrees here this afternoon. . .

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    2. That's creepy. 34 and snowing here.

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  14. New post on "You've Got to Know When to Fold 'Em: Origami, Science, and Engineering" is now up!

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