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), but with a different kind of mouth than common species, made for hunting prey in open waters, with a strong lower jaw, similar to modern beluga sturgeon.
Strongylosteus is a large member of the family Chondrosteidae and the largest non-reptilian marine vertebrate in the Posidonia Shale, with a size between 3m (10feet) and 4.5m (14.8feet), and an estimated weight over 800 kg to 1 tonne.
Strongylosteus has been suggested as a junior synonym of Chondrosteus, although there haven't been any new revisions about the status of the genus.[3]