After 100 years: a detailed view of an eumalacostracan crustacean from the Upper Jurassic Solnhofen Lagerstätte with raptorial appendages unique to Euarthropoda

The Solnhofen Konservat-Lagerstätte yields a great number of remarkably preserved fossils eumalacostracan crustaceans that help us understand the early radiation several groups with modern representatives. One fossil from there, Francocaris grimmi Broili, 1917 is small shrimp-like crustacean originally described about 100 years ago as mysidacean (opossum shrimps and relatives) latest Kimmeridgian – Tithonian (Upper Jurassic) Lithographic Limestones Southern Germany. New material exceptionally specimens, allied imaging techniques (mostly composite fluorescence microscopy), allows to provide detailed re-description this species. most striking feature an extremely elongated thoracopod 7 its distal elements forming spiny sub-chela. This character supports sister group relationship Eucopiidae, ingroup Lophogastrida, pelagic peracaridans common in marine environments throughout world. We also discuss other supposed representatives identifying all them problematic at best. structure sub-chela F. indicates original use raptorial behaviour. appears be unique possessing such far posterior sub-chelate appendage major structure. In Euarthropoda which appendages occur are used for food intake, they usually closer mouth.