PARALEPIDIDAE BONAPARTE, 1835

FAMILY PARALEPIDIDAE BONAPARTE, 1835 View in CoL View at ENA

SUBFAMILY † HOLOSTEINAE PROKOFIEV, 2005

Diagnosis (emended from Prokofiev, 2005): Large-sized paralepidids (most of the specimens reach about 60 cm SL) characterized by a rigid trunk with opposing dorsal and anal-fins posteriorly displaced on the posterior half of the body; dorsal-fin origin located on or slightly behind the vertical of the anal-fin origin; at least 18 dorsal-fin rays; high number of vertebrae (70– 112); caudal vertebrae 25–40% of the total number; extended series of epineurals and epipleurals reaching the caudal region; body covered by small scales or totally naked; large and dorsoventrally symmetrical caudal fin; (apparent) absence of adipose fin.

I n c l u d e d g e n e r a: † H o l o s t e u s A g a s s i z, 1 8 3 5, † Pavlovichthys Menner, 1948 .

Remarks: The subfamily † Holosteinae was erected by Prokofiev (2005) based on putatively unique synapomorphies shared by † H. esocinus Agassiz, 1835 , from the Eocene of Monte Bolca and †‘ Holosteus’ mariae ( Menner, 1948) from the lower Oligocene deposits of Caucasus ( Russia) and Carpathians ( Romania). According to Prokofiev (2005), these features include a lower jaw joint located in front of the level of the anterior margin of orbit, dorsal-fin origin located behind the anal-fin origin, about 70–100 vertebrae, at least ten branchiostegal rays, large fang-like teeth on the dentary and about 25 rays in both anal and pelvic fins. However, the lack of a comprehensive revision of the Eocene species from Monte Bolca prevented the recognition of the actual nature of their relationships. The exquisitely preserved specimens from the Eocene of Monte Bolca described herein are certainly related to the Oligocene taxon and clearly belong to the subfamily †Holosteinae, being characterized by a rigid trunk with both median fins displaced on the posterior half of the body, a dorsal fin with at least 18 rays whose origin is located slightly behind the vertical of that of the anal fin and a high number of vertebrae (70–110). Three additional synapomorphies were also recognized, including caudal vertebrae of 25–40% of the total number, intermuscular bones extending posteriorly and reaching the caudal region and (apparent) absence of an adipose fin. A number of features, however, provide robust evidence of the separate generic status of the Eocene and Oligocene species (see below).