Current issues with conodont tissues: using multi-analytical methods to unravel the conodont conundrum

ABSTRACT: Conodonts are a highly diverse group of chordates that thrived in prehistoric oceans from the late Cambrian to Late Triassic and are widely known from their isolated skeletal remains. The ecology of this animal has puzzled scientists for years, as the majority of studies are based upon information solely obtained from these teeth known as elements. This is further complicated due to the rarity of soft body remains that are often applied as the only analogue for all conodont taxa. These elements grew by lateral accretion of enamel-like hydroxyapatite throughout the animal’s life, which provides a somewhat continuous record of growth, potentially storing information about the life of the animal itself within these tissues. Here we attempt to answer the question “How much information about an animal’s mode of life can one obtain from an isolated tooth?”. With a combination of scanning electron microscope techniques, we can analyse the chemistry, crystallography and growth, unlocking this invaluable information. These methods, when used in combination, have been used to quantify an animal’s ontogeny, growth rates, ecology, function, and even the level of control on biomineralization that drove the evolution of the first teeth