What are Conodonts?
You’ve seen Tyrannosaurus Rex and — admit it — you were impressed. Maybe you saw Sue, in the Chicago Field Museum, purchased for 6 million dollars at auction. Does discovering the toothy fossil of an ancient hunter seem like an impossible dream? Guess again. You might be surprised to find that rocks in your own backyard could contain tiny, ancient objects that are as vicious-looking as any Tyrannosaur jawbone — and are ten times older. These remarkable teeth belong to extinct marine creatures called conodonts. Tiny, jaw-like structures the size of a grain of sand, these”cone-teeth” were the first cellular bone ever to be deposited in ocean sediments laid down during the Paleozoic era about 250 to 500 million years ago, first appearing long before land animals, fish or other creatures with backbones. (Dinosaurs became extinct about 65 million years ago.) Conodonts may have been ancestral to modern vertebrates, and their teeth were complex structures that were clearly specialized for
Conodonts are a group of extinct vertebrates that resemble eels. They swam the oceans of the world between the late Cambrian and late Triassic period (about 500 to 200 million years ago). Only about a dozen body fossils of conodonts have been uncovered —they are mostly known for fossils of their unusual feeding apparatus, called conodont elements. Paleontologists hesitate to call these elements “teeth” because their complex arrangement in the mouths of conodonts was unlike any known arrangements of teeth. Conodont elements are phosphatic microfossils found in great numbers in the relevant strata, but always in isolation. Conodont elements are so common that they can easily be isolated from paleozoic rock using acetic acid. For many decades, conodonts were only known from their teeth. It wasn’t until the early 1980s that fossils of the “conodont animal” were found. Despite the discovery of conodont elements clearly preserved in place with conodont animals, they are still paleontolgists
The conodonts were previously placed in a separate phylum (Phylum Conodonta), because their affinities were unknown. The current interpretation places them with the Chordates in Phylum Chordata. Conodont elements. Note that the color is indicative of thermal history and burial temperatures. Darker color indicates higher temperature. Temperatures are important to determine whether petroleum may have been generated in the rock, or whether temperatures were too high for petroleum to be preserved. Name: Conodont means “cone” + “teeth” (dont) Chief characteristics: • Conodont elements are microfossils (fossils that are so small that you need a microscope to examine them). Most conodont elements are 0.5 – 1.5 mm (some up to 10 mm, and some as small as 0.1 mm). • They are composed of a calcium phosphate variety of the mineral apatite (calcium fluorapatite). • Individual conodont elements resemble cone-shaped teeth, or consist of bars with rows of tooth-like denticles, or irregular knobby plat
