Ovalicaris wulforum sp. nov., a new thylacocephalan from the Late Jurassic Solnhofen Archipelago, and a re-examination of Dollocaris michelorum Polz, 2001

Laminated limestones from quarries in the vicinity of Solnhofen preserved remains of a diverse and complex shallow marine ecosystem. The so-called Solnhofen[-er] Plattenkalke are famous for their exceptionally well-preserved fossils of more than 1600 described species of extinct plants and animals. They have yielded an important pancrustacean palaeodiversity, including four species of Thylacocephala, a peculiar ingroup of fossil marine pancrustaceans. Two of these species, Mayrocaris bucculata and Clausocaris lithographica , have been the subject of several studies, in contrary to Dollocaris michelorum , which, after its original publication, has received little attention in the published literature. In this study, we describe a new species, Ovalicaris wulforum sp. nov., based on a newly discovered specimen. In addition, we re-examine D . michelorum based on new material . Additional morphological features of its shield are reported, including ornamentation on its margins (serrations, crenations) and surface (punctuations). The re-examination of D. michelorum leads to important insights into the impact of taphonomy on intra-specific morphological variability of thylacocephalans. Finally, we discuss the taxonomic diversity of Thylacocephala in the Solnhofen Lagerstätten and compare it with other important thylacocephalan faunae.