OBSERVATIONS ON THE HEAD ANATOMY OF THE ABYSSAL OPHIDIIFORM GENUS TYPHLONUS GUNTHER 1878, WITH COMMENTS ON ITS PHYLOGENETIC-RELATIONSHIPS

This paper describes some osteological and soft anatomical features of the head of the abyssal ophidiiform fish Typhlonus nasus Gunther 1878 Comparison of these with similar features described previously for ot her ophidiiform taxa suggest that, phylogenetically, Typhlonus belongs to the same group as Acanthonus and other abyssal forms; its closest relative may be Barathrodemus. Typhlonus has several unique features, including a greatly thickened supraoccipital, massive symplectic and e xtended premaxillary ascending processes.