What is "rhombichthys"

Rhombichthys intoccabilis is an extinct clupeomorph which existed in West Bank during the upper Cretaceous period.

The adults of R. intoccabilis had a very deep, scute-covered belly. In conjunction with the high, triangular dorsal fin, the belly gives the fish a rhombus-shaped body profile, hence the generic name. The juveniles, in contrast, had a far shallower belly, having a rounded profile.