There is no general model for occlusal kinematics in conodonts

Knowledge of conodont element function is based largely on analysis of morphologically similar P₁ elements of few comparatively closely related species known from abundant articulated remains. From these, a stereotypical pattern of rotational occlusion has been inferred, leading to the suggestion that this may represent a general model for ozarkodinin P₁ elements at the very least. We test the generality of this occlusal model through functional analysis of Pseudofurnishius murcianus P₁ elements which, though superficially similar to homologous elements in gnathodids, evolved their platform morphology independently, through a different mode of morphogenesis, and in a different topological position within the element. Our integrated functional analysis of several articulated clusters of P₁ elements encompassed physical and virtual occlusal analyses, constrained by microwear and sharpness analyses. All of the evidence supports an occlusal model in which the Pseudofurnishius P₁ elements occluded with the dextral blade located between the rostral face of the sinistral blade and the first cusp of the rostral primary process. In achieving this, the dorsal and ventral blades guided the opposing elements, and the rostral processes of both elements guided the final stages of precise occlusion. Spalling and microwear on the non‐occlusal side of the element evidence malocclusion, requiring the complete separation of elements within the occlusal cycle. This occlusal cycle is entirely linear, orthogonal to the plane of attachment of the elements. Evidently, the rotational occlusal model is not general for P₁ elements, even for ozarkodinins, and it is likely that among conodonts occlusal kinematics are as disparate as element morphologies. Attempts to elucidate the diversity of occlusal kinematics and, therefore, feeding ecologies of conodonts will be repaid by an understanding of the role of this important abundant and diverse clade in Palaeozoic and Mesozoic marine ecosystems.     

Genetic composition of the Jadro softmouth trout following translocation into a new habitat

Genetic founder effects of a historical translocation (1965; app. 12 generations ago) of endangered softmouth trout from the only remaining indigenous population to an adjacent uninhabited river were investigated. A comparison of 15 microsatellites from contemporary samples in both the source and re-established populations indicated a very low level of genetic diversity within the two populations. Furthermore, considerable differences in estimates of variability and effective population sizes were detected between populations, but no recent bottlenecks were evident. Our data suggest that the re-established population has lost variation due to genetic drift associated with founder effects following the translocation. Accordingly, in relation to management, we suggest that the re-established population could serve as a secondary source of individuals to buffer possible extinction due to demographic events. Finally, conservation initiatives to enhance the census population size and increase levels of variability in the re-established population are proposed. Electronic Supplementary Material Supplementary material is available in the online version of this article at and is accessible for authorized users.