Osteichthyan Fishes from the uppermost Norian (Triassic) of the Fuchsberg near Seinstedt, Lower Saxony (Germany)

Abstract

Fishes from the uppermost Norian Fuchsberg Quarry near Seinstedt are represented by two taxa that we interpret as a teleosteomorph (complete specimens) and actinistian (scales). Seinstedtia parva gen. et sp. nov. is described; although it was proposed as a possible semionotiform, this study reveals that Seinstedtia possesses a combination of teleosteomorph features, for instance: characteristic pholidophoriform-shaped cranial roof; fusion of skull roof bones; three dorso-posterior infraorbitals, including an enlarged infraorbital 3; one suborbital bone; movable premaxilla; and characteristic-shaped preopercle. In parallel, Seinstedtia possesses a head gently curved anteriorly, with lower jaw protruding slightly in front of upper jaw; supraorbital 1 forming most of antero-dorsal margin of circumorbital ring; one supramaxilla; three extrascapulae; cleithrum with short and broad lower arm; and enlarged clavicle. This character combination places Seinstedtia as a teleosteomorph, family incertae sedis. This fish (total length ca. 50 mm) and some pholidophorids (ca. 70 mm or less; Parapholidophorus nybelini and Pholidoctenus serianus) represent the known smallest teleosteomorphs that inhabited Europe during the Norian. The isolated scales are elasmoid of amioid type ornamented with the elongated ridges of actinistians. This diversity of teleosteomorphs and actinistians in Fuchsberg Quarry during the Triassic indicates a connection to a marine environment.