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Science

Jawless Creature Had the World's Sharpest Teeth 53

Posted by samzenpus
from the his-bite-is-worse-than-his-bark dept.
ananyo writes "An extinct primitive marine vertebrate had the sharpest dental structures ever known — with tips just one-twentieth of the width of a human hair, but able to apply pressures that could compete easily with those from human jaws. The razor-sharp teeth belonged to conodonts, jawless vertebrates that evolved some 500 million years ago in the Precambrian eon and went extinct during the Triassic period, around 200 million years ago. The creatures roamed the planet for longer than any other vertebrate so far–– and despite their lack of jaws, they were the first creatures to evolve teeth (abstract)."
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Jawless Creature Had the World's Sharpest Teeth

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  • Is there any compensation that has to be applied to fossils which are over 200 million years old? Such as erosion etc?
    • Re:How accurate? (Score:5, Informative)

      by Anonymous Coward on Wednesday March 14, 2012 @08:46PM (#39359671)

      Not as much as you would think. Conodonts are composed of calcium phosphate -- the same stuff as our teeth. It's fairly durable mineral. They are usually extracted from rocks in almost unaltered state. Conodonts do get broken and worn like any other sediment particle, so sometimes they're a bit beaten up, but often they are nearly intact despite being fairly fragile-looking structures. Sometimes their surfaces even show wear from the time when the animal was alive (i.e. tooth wear). Growth lines and other structures are visible internally.

      The rest of the animal -- the body -- is soft tissues, so that part rarely preserves and is flattened even when it is preserved, however, multiple specimens compressed in different orientations reveal the 3D structure. There are also slightly more robust structures around the eye sockets (sclerotic capsules).

    • by Dahamma (304068)

      Is there any compensation that has to be applied to fossils which are over 200 million years old?

      No, I think their tooth patents are all expired...

  • by buchner.johannes (1139593) on Wednesday March 14, 2012 @07:51PM (#39359243) Homepage Journal

    of this eel-like creature [wikipedia.org]... looks like we don't know much about them aside from their teeth?

    Meteorites suck. I mean blow.

    • There is no particular reason to think the Triassic-Jurassic extinction was caused by an impact event.

  • Freaky Beasties (Score:5, Interesting)

    by Sponge Bath (413667) on Wednesday March 14, 2012 @07:54PM (#39359259)

    Here [le.ac.uk] are some speculative drawings of the creatures. Getting caught in a swarm of thrashing sharp dental structures would make a good horror film.

  • Having evolved to chew through solid rock... They bored into the earth, and have evolved to make sustainable life energy in the heat below the earth's mantle... What's that noise?... Come closer to the campfire.
    • Having evolved to chew through solid rock... They bored into the earth, and have evolved to make sustainable life energy in the heat below the earth's mantle... What's that noise?... Come closer to the campfire.

      If they are smart, they will evolve into goa'uld [wikipedia.org], and be preserved forever on Netflix [netflix.com]...

  • by PCM2 (4486) on Wednesday March 14, 2012 @08:25PM (#39359523) Homepage

    Just when you thought it was safe to go back in the water ... JAWLESS!

  • by pauljlucas (529435) on Wednesday March 14, 2012 @08:47PM (#39359681) Homepage Journal
    Aren't these [wikipedia.org] living creatures related?
    • Re:Hagfish (Score:4, Interesting)

      by Randle_Revar (229304) <kelly.clowers@gmail.com> on Wednesday March 14, 2012 @09:51PM (#39360127) Homepage Journal

      Everything is related, it is a question of how closely. Seems some taxonomies put them near the hagfish class and the lamprey class, however a 2010 paper argues they are not Vertebrata at all, or even Craniata.

    • by vtcodger (957785)

      Aren't hagfish (technically Agnatha) related? Yes, but probably not too closely? They are about as old. But the fossil information on early vertebrates and similar critters is very sparse. It's hard to tell all that much about them. For example, there is a phylum of critters called Chaetognaths whose fossils somewhat resemble both fish and conodonts. They have eyes, fins, teeth. But unlike the conodonts, they survived until the present allowing biologists to determine that internally, the chaetognats

    • Fascinating. Thanks for that link.
  • with tips just one-twentieth of the width of a human hair, but able to apply pressures that could compete easily with those from human jaws

    The size of the surface area has no bearing on the amount of pressure that can be applied because pressure is force per unit area.

    • if pressure is force per unit area then it sounds like area and pressure are related - the smaller area for the same force will have higher pressure because force divided by a smaller value will continue to increase, right?
    • The size of the surface area has no bearing on the amount of pressure that can be applied because pressure is force per unit area.

      Try again. Try harder.

  • Is jawless and has pretty sharp (figurative) teeth.
  • Given that it had no jawbone, it only makes sense that the teeth be sharp to still "get thru the point".

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