AMAKUSAICHTHYS, 2018

Genus AMAKUSAICHTHYS

Yabumoto, Hirose, and Brito, 2018

Included species. Amakusaichthys goshouraensis Yabumoto, Hirose, and Brito, 2018 . Amakusaichthys benammii sp. nov. described below.

Emended diagnosis. Ichthyodectiform fish with an extended ethmoid region of the skull; small mouth; supraoccipital crest shallow and short; parietals medially fused; lower jaw-quadrate articulation located ahead of the orbit; maxilla comparatively short and sinuous; lower jaw rectangular and relatively short; jaw teeth small, conical, and evenly sized and spaced; ethmopalatine bone long and far from the nasal capsule, with osseous membranous suturing projections and ventral articular facets located below the rostrodermethmoid bone; palatine head high, disk-like malleolus, and with a ventral expanded wing; preopercle with a long ventral limb and the posterior edge intensely fringed; preopercular sensory canal with numerous curved parallel branches in the preopercle horizontal limb; pelvic fin placed very close to the origin of the anal fin; unpaired fins located far in the back of the trunk, including a dorsal fin placed slightly ahead of the long anal fin; rays of the caudal dorsal and ventral lobes anteriorly extended, covering most of the caudal skeleton; neural arches of the most posterior preural centra have dorsoanterior saddle-shaped processes supporting the adjacent anterior neural spine; hypural 1 spatuliform; hypural 2 large and triangular with a prominent dorsal ridge bent laterally, forming a triangular structure resembling the folded corner of a blanket on the bed that is pierced by three large pores; articular heads of hypurals 1–2 and parahypural broad an in lateral contact; hypural 3 slightly shorter than hypural 2; trunk entirely covered with large thin cycloid scales ornamented with numerous concentric circulii, central puntae, and scarce anterior and parallel radii.