Friday, December 23, 2011


Conodonts were bizarre, fish-like probable chordates that may have resembled modern lampreys. They first evolved in the Cambrian, or possibly even the Precambrian, and died out in the Triassic-Jurassic extinction.

Conodonts were eel-shaped in form and most had large eyes, at least in comparison to the body. They had various toothy blades in the mouth to form what is known as "the conodont apparatus," which vaguely resembles the radula of a snail or slug.

Conodonts were probably capable of maintaining a cruising speed, but could not perform bursts of speed because their eel-like form would probably get them all tangled up. They would then be easy prey for any kind of predator trying to eat them. They probably swam in about the same style as an eel or loach. Although they had sharp teeth, they probably were not predators. Instead, they supposedly used "the conodont apparatus" as a sort of baleen to filter plankton from the water.

The largest conodont that has been found so far is Promissum, which reached lengths of 16 inches. Specimens of Promissum can be found in the Soom Shale of South Africa. Unlike most conodonts, Promissum had smaller eyes relative to body size. Promissum was about as long as an average house cat's body, without the head or tail.

The fist conodont specimens found were its individual toothy bars known as "conodont elements."



  1. Heh. That critter looks like a sock puppet with googlie eyes. But what impressive teeth it has!

  2. Conodonts taste great! (With the right condiments)

  3. Hi Art,

    Good writeup

    My wife did a paper on conodonts at BYU using them for dating sedimentary rocks in a region of Utah (useful in the field of oil exploration) and has some of these on slides.

    She is very proud of them as she had to extract them from the rock they were embedded in. Crushing and dissolving the Limestone matrix in formic acid (a organic acid which would not affect the apatite the conodonts were made out of), screening the remaining material, and then using a microscope, a very fine stylus, and packing tape dampened slightly.

    She would dab the stylus on the damp packing tape picking up some adhesive, and then picked up one conodont fossil, adhering it to a slide

    here´s a picture I took of one of her slides she let me hold -- -- with my thumb for scale.

    Here´s a Scanning Electron Microscope image of one (with the 100-uM scale bar)