TryblidiumTryblidium is a paleozoic genus of Ordovician and Silurian monoplacophorans.The generic name comes from the Greek, which means patella.SpeciesSpecies in the genus Tryblidium include:Tryblidium acutumTryblidium arcticaTryblidium eratoTryblidium eubuleTryblidium exsertaTryblidium hyrieTryblidium modestumTryblidium niobeTryblidium nycteisTryblidium ovaleTryblidium ovatumTryblidium pileolumTryblidium reticulatumTryblidium rugosumTryblidium simplex ''Tryblidium thorsteinssoni''