A new specimen of Adelophthalmus luceroensis (Eurypterida: Chelicerata) from the late Carboniferous (middle Missourian; Kasimovian) Kinney Quarry Lagerstatte of New Mexico

A new specimen of the eurypterid Adelophthalmus luceroensis KUES & KIETZKE, 1981, is described from the middle Missourian (Kasimovian; Late Pennsylvanian; late carboniferous) of the Kinney Quarry Lagerstatte of central New Mexico, U.S.A.. It reveals the enigmatic antero-medial triangular process (so-called 'doublure lock'), a possible labrum, chelicerae, and curled-up walking legs, enabling an emended diagnosis of the species. The taxonomy, respiratory palaeobiology and ecology of Adelophthalmus is reviewed: this longest-lived (Early Devonian to early Permian) and most diverse eurypterid genus is likely taxonomically oversplit and in need of revision; their paddles indicate that they were primarily aquatic (nektonic) predators and scavengers, but they were capable of brief terrestrial excursions to breed.