Ar. spinosissimus:

MNHN A-0352 (lectotype), MNHN 2005-0780 (3 paralectotypes), Guatemala, Izabal, Rio Polochic ; UMMZ 146070 (1, 1 partly skel.), Guatemala, Alta Verapaz; UMMZ 146086 (4, 1 partly skel.), Guatemala, Izabal, Rio Polochic ; UMMZ 190737 (25), UMMZ 197249 (7, 1 C&S, XR, 7 dig.), Guatemala, Izabal, 19 km SW of Livingston, RioPaujila on El Golfete .