X. stephanus (type species)

Abeliella, Acanthichnus, Acanthorhaphe, Aglaspidichnus, Agrichnium, Algites, Allocotichnus, Amphorichnus, Annelidichnium, Anobichnium, Archaeichnium, Archaeonassa, Ardelia, Arenicolites, Arthraria, Arthrophycus, Arthropodichnus, Asaphoidichnus, Asteriacites, Asterichnites, Asterichnus, Asterophycus, Asterosoma, Aulichnites, Balanoglossites, Baroccoichnites, Bascomella, Beaconichnus, Beaconites, Belorhaphe, Bergaueria, Bifasciculus, Biformites, Bifungites, Bifurculapes, Bostricophyton, Brachyzapfes, Brancichnus, Brooksella, Brookvalichnus, Bunyerichnus, Calcideletrix, Calciroda, Calycraterion, Cambrorhytium, Caulostrepsis (syn. Polydorites), Chaetophorites, Chomatichnus, Chondrites, Circulichnis, Climactichnites, Clionoides, Clionolithes, Cochlichnus, Conchifora, Conchotrema, Condranema, Conichnus, Conispiron, Conopsoides, Conostichus, Copeza, Coprinisphaera, Corophioides, Cosmorhaphe, Crossopodia, Cruziana, Ctenopholeus, Curvolithus, Cycloichnus, Cylindrichnus, Cylindricum, Dactyloidites, Dactylophycus, Daedalus, Daimonelix, Dendrina, Dendrotichnium, Desmograpton, Dictyodora, Dictyoporus, Didymaulichnus, Dimorphichnus, Diplichnites, Diplocraterion, Diplopodichnus, Diplopodomorpha, Echinospira, Eugyrichnites, Fascifodina, Fascisichnium, Felixium, Filuroda, Fraena, Fucusopsis, Fustiglyphus, Gastrochaenolites (syn. Paleolithophaga), Glockeria, Gluckstadtella, Goettingenia, Goniadichnites, Gordia, Granularia, Graysonia, Gyrichnites, Gyrochorte, Gyrolithes, Gyrophyllites, Haentzschelinia, Halimedides, Halopoa, Hamipes, Haplotichnus, Harpepus, Helicodromites, Helicolithus, Helicorhaphe, Heliochone, Helminthoida, Helminthopsis, Hexapodichnus, Histioderma, Hormosiroidea, Hydrancylus, Ichnocumulus, Ichnyspica, Ichnyspicam, Ichthyoidichnites, Imbrichnus, Imponoglyphus, Incisifex, Iramena, Irredictyon, Isopodichnus, Ixalichnus, Keckia, Kingella, Kouphichnium, Kulindrichnus, Kullingia, Laevicyclus, Laminites, Lanicoidichna, Lapispecus, Lapispira, Lennea, Lenticraterion, Lithographus, Lobichnus, Lockeia, Lophoctenium, Lorenzinia, Macanopsis, Maeandropolydora, Mammillichnis, Margaritichnus, Mawsonites, Megagrapton, Megathrix, Merostomichnites, Mesichnium, Mesonereis, Micatuba, Minichnium, Mixoteichichnus, Monocraterion, Monomorphicnus, Mycelites, Myriapodites, Myzostomites, Namapoikia, Neonereites, Neoskolithos, Nereites, Nygmites, Octopodichnus, Oldhamia, Oniscoidichnus, Ophiomorpha, Ormathichnus, Ostreoblabe, Palaeachlya, Palaeohelminthoida, Palaeopede, Palaeoperone, Palaeophycus, Paleobuprestis, Paleodictyon, Paleohelcura, Paleoipidus, Paleomeandron, Paleoscolytus, Parahaentzscheliana, Paratisoa, Pennatulites, Permichnium, Petalichnus, Phagophytichnus, Phoebichnus, Pholeus, Phycodes, Phycosiphon, Phyllodocites, Pilichnia, Plagiogmus, Plangtichnus, Planolites, Podichnus, Polyisthmus, Polykampton, Protichnites, Protolyellia, Protopaleodictyon, Protovirgularia, Psammichnites, Pseudobilobites, Pseudopolydorites, Pterichnus, Pteridichnites, Quebecichnus, Radiichnus, Radionereites, Radomorpha, Ramosulichnus, Repentella, Rhabdoglyphus, Rhizocorallium, Rhizostomites, Rodocanalis, Rogerella, Rogerella, Rosselia, Rusophycus, Sabellarifex, Sabellarites, Saerichnites, Sagittichnus, Saportia, Scalarituba, Scoyenia, Seminolithes, Simonizapfes, Siphonites, Skolithos, Specus, Spirodesmos, Spirophycus, Spirophyton, Spirorhaphe, Spongeliomorpha, Spygoria, Steigerwaldichnium, Stellascolites, Stelloglyphus, Stellostomites, Stichus, Stipsellus, Strobilorhaphe, Subglockeria, Sublorenzinia, Sustergichnus, Syringomorpha, Taenidium, Talpina, Tambia, Taphrhelminthopsis, Tarrichnium, Tasmanadia, Tasselia, Teichichnus, Teratichnus, Teredolites (syn. Martesites), Tetraichnites, Thalamophaga, Thalassinoides, Tigillites, Tisoa, Topsentopsis, Torrowangea, Trachomatichnus, Treptichnus, Triavestigia, Trichichnus, Trichophycus, Trichoplax, Trisulcus, Trypanites, Tuapseichnium, Tylichnus, Uchirites, Umfolozia, Unarites, Urohelminthoida, Vermiforichnus, Volkichnium, Walpia, Worthenella, Yakutatia, Yunnanomedusa, Zapfella, Zoophycos