Praearcturus

Praearcturus (lit. 'before Arcturus') is an extinct genus of large scorpion known from the Devonian period of what is now Britain. The genus contains a single species, Praearcturus gigas, the sole member of the family Praearcturidae. The definitive identity of Praearcturus was historically considered enigmatic, first described as a giant isopod and subsequently argued as a myriapod or eurypterid. None of the proposed identifications were agreed by various researchers, until the scorpion interpretation was suggested in 1980. While some researchers have expressed uncertainty regarding the authenticity of this interpretation, a first hand redescription of the lectotype and other assigned fossil remains using photographs and CT scans thoroughly supported that Praearcturus is most likely a scorpion. Proposed junior synonyms include Bennettarthra and Brontoscorpio, the latter of which has been also previously argued to be a member of the same family.