An Eocene soldierfish (Teleostei: Holocentridae) from Monte Baldo (NE Italy)

An Eocene holocentrid fish is described herein from the southern sector of Monte Baldo, NE Italy. Although the fossil lacks the posterior portion of the body and the dense scale covering prevents the observation of the postcranial skeleton, it shows a set of morphological characters (e.g., transverse crest on the dorsal surface of supraoccipital; skull roof ornamented by ridges and channels; frontals extending posteriorly over the parietals and supraoccipital; eyes large; opercle with weakly serrated posterior margin; maxilla expanded posteriorly; two supramaxillae) that support its assignment to the family Holocentridae. Moreover, the premaxilla with an ascending process shorter than the alveolar one, the quadrate-mandibular joint located behind the posterior margin of the orbit, and the absence of a prominent preopercular spine concur to suggest a possible attribution to the subfamily Myripristinae. The family Holocentridae is represented today by squirrelfishes and soldierfishes that inhabit warm shallow waters on coral reefs and rocky bottoms up to 200 m of depth. This new specimen represents one of the few fossils of this family recovered in the Eocene deposits of the western Tethys, providing support to the hypothesis that the evolutionary origin of holocentrid fishes took place in the warm and shallow paleobiotopes of this region.