A possibly deep branching artiopodan arthropod from the lower Cambrian Sirius Passet Lagerstätte (North Greenland)

Artiopoda was a diverse group of Palaeozoic euarthropods that proliferated in the early Palaeozoic, epitomized by ubiquitous trilobites. Their possible phylogenetic position outside mandibulates and chelicerates offers potential for understanding evolution more detail. However, this opportunity remains unexploited given identification deep-splitting artiopodans to be fully explored. Here, we describe new non-trilobite artiopodan from lower Cambrian Sirius Passet Lagerstätte, North Greenland. Thulaspis tholops gen. et sp. nov. is large species with broad, domed head shield, followed trunk consisting 15 thoracic tergites small pygidium, giving body an ovoid appearance when viewed dorsally. distinctive its rounded genae anterior pleural tips, as well short spines posteriorly. A heart-shaped hypostome lobe present. Appendages, partly obscured tergal skeleton, have many moderate length gnathobasic spines, flap-like exopods fringe setae. Cladistic analyses recover sister taxon Squamacula, genus found Chengjiang Emu Bay Shale biotas, either polytomy number taxa or all other artiopodans, indicating important role roots anatomy evolution.