Lehmanosteus

{{Short description|Genus of extinct fish}}

{{Automatic_taxobox

| fossil_range = Early Devonian, {{fossilrange|419|393}}

| taxon = Lehmanosteus

| authority = Goujet, 1984

| subdivision_ranks = Species

| subdivision =

• {{extinct}}Lehmanosteus hyperboreus Goujet, 1984 (type)

}}

Lehmanosteus is an extinct monospecific genus of arthrodire placoderm fish, named after French paleontologist Jean-Pierre Lehman. The type species Lehmanosteus hyperboreus was described in 1984, and was found in Early Devonian strata of the Wood Bay Formation on the island of Spitsbergen, Svalbard in Norway.{{cite book|last=Goujet|first=D.|year=1984|title=Les poissons placodermes du Spitzberg: Arthrodires Dolichothoraci de la Formation de Wood Bay(Dévonien inférieur)|publisher=Editions Centre National Recherche Scientifique, Cahiers de Paléontologie|location=Paris}}

It is one of the more basal members of the order Arthrodira, as shown in the cladogram below:{{Phylogeny/Actinolepidoidei}}