Between Death and Data: Biases in Interpretation of the Fossil Record of Conodonts

The fossil record of conodonts may be among the best of any group of organisms, but it is biased nonetheless. Preand syndepositional biases, including predation and scavenging of carcasses, current activity, reworking and bioturbation, cause loss, redistribution and breakage of elements. These biases may be exacerbated by the way in which rocks are collected and treated in the laboratory to extract elements. As is the case for all fossils, intervals for which there is no rock record cause inevitable gaps in the stratigraphic distribution of conodonts, and unpreserved environments lead to further impoverishment of the recorded spatial and temporal distributions of taxa. On the other hand, because they are resistant to abrasion and can withstand considerable metamorphism conodonts can preserve evidence of otherwise lost sequences or environments