A new cheirolepidid fish from the Middle-Devonian of Red Hill, Nevada, USA

A new species of Cheirolepis is described from the Middle-Upper Devonian of Nevada, USA. Comparisons with Cheirolepis trailli and C. canadensis show that the new species is characterized by a unique combination of characters, e.g., a small orbit, a short spiracular slit, a very elongate and narrow dermosphenotic, a long sutural connection between dermosphenotic and supratemporal, and cranial ornamentation including numerous ganoine ridges and few, small tubercles. A pineal foramen is absent, as are the intertemporal and quadratojugal bones. A series of small pores confirm the presence of a jugal pit line; however, a continuation of the jugal pit line and the infraorbital canal has not been observed. The new material enriches the available information on the morphology of Cheirolepis, particularly on the palatoquadrate region and the pectoral girdle, and reveals that there is variation in the cranial morphology of the species of Cheirolepis that cannot be ignored, e.g., the relationship of the dermosphenotic with other bones, and the presence of notch(es) in the nasal bone and preorbital bone. The structure of the rostral region of Cheirolepis still remains unclear due to incomplete preservation.