Early teleost otolith morphogenesis observed in the Jurassic of Franconia, Bavaria, southern Germany

Abstract

The otoliths described in this study are from the late Pliensbachian of the Buttenheim clay pit near Bamberg, Franconia, northern Bavaria, and represent one of the earliest teleost otolith assemblages known so far. A total of 351 otoliths have been recovered, many of which are well-preserved and of sizes that indicate they originated from adult specimens and can be considered morphologically mature. The assemblage contains seven species, four of them stem teleosts of the genus Leptolepis and three from the enigmatic otolith-based genus Archaeotolithus, which cannot be attributed to a firm systematic position. We describe three species as new: Leptolepis buttenheimensis sp. nov., Leptolepis steberae sp. nov. and Archaeotolithus doppelsteini sp. nov. In addition, we review 49 otoliths from the original material of Schröder’s (1956) publication that were uncovered at the University of Erlangen. This material stems from the late Toarcian/early Aalenian and early Callovian of Franconia. In this review, we accept only a few of the species described by Schröder as valid. The otolith associations from the Early and Middle Jurassic of Franconia, in combination with previously published material, allow for an assessment of the morphogenesis of early teleost otoliths. Early Jurassic teleost otoliths are represented by a few common and long-ranging species. A sudden burst in otolith diversity seems to have occurred during the Middle Jurassic and is first evident in the Bathonian.