Morphological variation of Palmatolepis Devonian conodonts: species versus genus

In extinct animals such as conodonts, the concept of species cannot be biologically tested and therefore suffers from uncertainty. Yet, a prerequisite to paleobiological interpretation is to determine the relevant scale for investigating patterns of size and shape variability. Such patterns have been analysed for the conodont Palmatolepis Pa-elements based on two different approaches which are compared. A previous study considered separately the species recognised within Palmatolepis . A drawback of this approach is to ignore the large number of indeterminate specimens. We propose here to analyse together all the Palmatolepis Pa-elements. The results of both methods are comparable, but the ‘generic’ approach seems more efficient in displaying fine-scale shape variations. This discrepancy may be due to the fact that the generic approach, taking all specimens into account, allows for analysing allometric relationships. Hence, paleobiological processes involved in the morphological variability can be addressed. .