Taxonomic status of the caturid genera (Halecomorphi, Caturidae) and their Late Jurassic species

Abstract

Caturids are among the best-known predatory ray-finned fishes of the Mesozoic. Although there is consensus about their sister-group relationship to Amiidae (Holostei, Amiiformes), their diversity, ingroup phylogenetic relationships and evolutionary history are still very poorly understood. Caturidae is currently restricted to Caturus and Amblysemius , each with two species. Among them, C. furcatus has become the wastebasket taxon for the group. Our revision of nearly 40 species based on the original descriptions, type and referred material led to significant results changing the picture of caturid diversity in the Late Jurassic. Four specific names are unavailable. Due to insufficient information in the original descriptions, lack of diagnostic features in the type material, or the complete lack of type material, 13 nominal species are nomina dubia. Two species currently considered junior synonyms represent distinct taxa. Strobilodus giganteus is removed from Caturidae. Caturus cliftoni , Thlattodus and Ditaxiiodus are tentatively referred to Strobilodus . The fossil record of Caturoidea is restricted to the Jurassic and earliest Cretaceous. The group apparently underwent significant diversification during the Late Jurassic, as indicated by the increase in the number of taxa and the dispersal of the group outside Europe, which had already begun in the Middle Jurassic.

The early fossil record of Caturoidea (Halecomorphi: Amiiformes): biogeographic implications

“…The known fossil record of the Halecomorphi starts in the Lower Triassic and the oldest record of Amiiformes is reported from the Upper Triassic (Norian) (López-Arbarello and Sferco, 2018; López-Arbarello and Ebert, 2023). A recent taxonomic revision of the Caturoidea (López-Arbarello and Ebert, 2023) shows that the known fossil record of the group is almost restricted to the Jurassic, and revealed an important diversi cation of this group during the Late Jurassic that is not only indicated by the increase in the number of taxa, but also by the dispersal of the group outside Europe, which had already started in the Middle Jurassic.…”

“…The known fossil record of the Halecomorphi starts in the Lower Triassic and the oldest record of Amiiformes is reported from the Upper Triassic (Norian) (López-Arbarello and Sferco, 2018; López-Arbarello and Ebert, 2023). A recent taxonomic revision of the Caturoidea (López-Arbarello and Ebert, 2023) shows that the known fossil record of the group is almost restricted to the Jurassic, and revealed an important diversi cation of this group during the Late Jurassic that is not only indicated by the increase in the number of taxa, but also by the dispersal of the group outside Europe, which had already started in the Middle Jurassic. Despite reaching their maximal diversity and dispersion in the Tithonian, the youngest records of the group in the earliest Cretaceous are limited to western Europe (Berriasian of Swanage, Dorset, United Kingdom; Berriasian-lower Valanginian of El Montsec, Lérida, Spain), suggesting a very rapid decline of the group at that time.…”