Conodonts have long been a mystery to the scientific community. They are represented in the fossil record by tooth-like mirofossils found as constituents in poorly cemented sandstones and shales or imbedded in limestone. Conodonts are made from the mineral apatite, just like human teeth, and therefore do not dissolve in weak acid. Those elements that are imbedded in limestone may be extracted by dissolving away the limestone host in leaving behind pristine conodont elements. From a paleobiological perspective, this method is fairly destructive because it destroys natural assemblages.
Conodonts were originally described by the embryologist C. H. Pander in 1856. Pander assumed they were teeth from an extinct Paleozoic Era fish. Subsequent workers believed them to be components of worms. Rare, extremely well preserved specimens have let most modern conodont paleontologists to agree that these animals were true vertebrates of the phylum Chordata. Also, these discoveries have confirmed the previously assumed notion that these animals were nektonic organisms having swum freely in the water column. For this reason they are found sedimentary deposits from a wide range of water depths. Because they were not living directly on the sea floor sedimentological evidence may tell us little about their life habits.
The uniqueness and abundance of conodont fauna in the rock record has been praised for its applications in the fields of biostratigraphy and paleiobiology. Recent developments in geology have used the chemical compositions of conodont elements to learn about climates and ocean conditions.