Strongylosteus | |
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Strongylosteus hindenburgi fossil, Staatliches Museum für Naturkunde Stuttgart | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | † Chondrosteiformes |
Family: | † Chondrosteidae |
Genus: | † Strongylosteus Jaekel, 1929 |
Species: | †S. hindenburgi |
Binomial name | |
†Strongylosteus hindenburgi (Pompeckj, 1914) | |
Synonyms | |
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Strongylosteus is an extinct genus of prehistoric ray-finned fish that lived during the early Toarcian age of the Early Jurassic epoch. [1] [2] Its type species is Strongylosteus hindenburgi (monotypy). It is related to modern sturgeon and paddlefish (Acipenseroidei). [2]
Strongylosteus hindenburgi is known from the Toarcian Posidonienschiefer Formation in southwestern Germany, specifically around Holzmaden and Dotternhausen. Initially identified by Pompeckj in 1914 as " Chondrosteus hindenburgi", hovewer the name was never formally published. Hauff (1921) mentioned it as a nomen nudum , and Hennig (1925) provided the first formal description, retaining the name but describing it in detail alongside additional specimens. [2] Jaekel (1929) later reassigned it to the new genus Strongylosteus, correcting its taxonomic position. [3]
Since the 1925 description, over a dozen specimens, including isolated bones and partial skeletons, have been noted in various museum collections, though many remain undescribed or misidentified. This include a juvenile specimen under one meter long, present in the Urwelt Museum Hauff, awaiting formal study that may reveal ontogenic shifts. [4]
Strongylosteus has been suggested as a junior synonym of Chondrosteus , although there haven't been any new revisions about the status of the genus. [5] There have also been suggestions of synonymy between Strongylosteus hindenburgi and Gyrosteus mirabilis, mainly due to incomplete descriptions and preservation issues. [5] However, a 2025 analysis of a new skull roof from the Toarcian Whitby Mudstone corroborated Strongylosteus as a distinct genus based on skull roof differences, such as the number of rostral bones, the presence of a medial parietal, and variations in bone proportions and ornamentation patterns. The morphological distinctions are consistent across specimens, ruling out ontogenetic or intraspecific variation. Authors also pointed out that a modern redescription and phylogenetic analysis of both Strongylosteus and Gyrosteus is still necessary to clarify their evolutionary relationships within Chondrosteidae. [4]
Strongylosteus was a large member of the family Chondrosteidae and the largest non-reptilian marine vertebrate in the Posidonia Shale, with the largest articulated specimen (SMNS 7790) measuring 3.2 m in total length. [4]