Boreosomus is an extinct genus of Triassic marine ray-finned fish. It was first described from the Arctic island of Spitsbergen, hence its genus name, but was later also discovered in other parts of the world. The type species is Boreosomus arcticus.
Boreosomus
Boreosomus gillioti fossil from Beroroha, Madagascar
Boreosomus slab and counterslab fossils at the Geological Museum in Copenhagen
Ptycholepiformes are an extinct order of prehistoric ray-finned fish that existed during the Triassic period and the Early Jurassic epoch. The order includes the genera Acrorhabdus, Ardoreosomus, Boreosomus, Chungkingichthys, Ptycholepis, and Yuchoulepis. Although several families have been proposed, some studies place all these genera in the same family, Ptycholepididae.
Ptycholepiformes
Scales of Ptycholepis bollensis
Triassic Boreosomus fossil
Jurassic Ptycholepis fossil