Bajaichthys

Bajaicthys elegans is an extinct Lutetian lamprid from the Monte Bolca Lagerstatten.

Anatomy and appearance
The holotype is four centimeters in length. It has a deep, oblong-shaped body, a deep, but short head, a long tail composed of 27 caudal vertebrae, a long, crest-like dorsal fin, a long, banner-like anal fin with 29 to 30 rays running from the posterior region of the body down the entire length of the tail, and two enormous, wing-like pelvic fins.

The holotype (and only known specimen) is regarded as the remains of a larval ("youthful") form due to its small size and due to its strong similarity to the larval form of trachypterid ribbonfish.

Taxonomic Status
B. elegans' taxonomic status is in doubt as it combines features of both taeniosomid lamprids (i.e., its larval form resembles those of oarfish and ribbonfish), and of bathysomid lamprids (the anatomy of the pelvis is extremely similar to that of sailfins )