Panderodus from the Waukesha lagerstätte of Wisconsin, USA: the anatomy of primitive macrophagous vertebrate predators

Conodonts are an extinct group of early vertebrates. Articulated fossils of their feeding apparatus (‘natural assemblages’) are rare, and preserved soft tissues vanishingly so. Here, a primitive conodont with preserved soft tissues is redescribed from the Waukesha Lagerstätte of Wisconsin, USA. Although the feeding apparatus of derived prioniodontid conodonts is well understood, together with the homologies between taxa, the same is not true of more primitive conodonts that have apparatuses composed entirely of coniform elements. The new data provide insight to the long-term problem of determining homology across different types of conodont feeding apparatus. The Waukesha Panderodus preserves an almost complete apparatus and comprises two parallel rows of elements that occluded across the sagittal plane. A pair of M elements lies at the rostral end of the apparatus, with four pairs of S elements located immediately caudal to them. Three pairs of P elements are identified at the caudal e...