Parent taxon: Gymnospermae according to J. M. Anderson et al. 2007
See also Doweld 2001
Sister taxa: Aethophyllum, Alatocarpus, Allicospermum, Araucariales, Arberiella, Archaeosperma, Barakaroxylon, Belemnopteris, Bennettitales, Birsinghpuria, Bulbospermum, Cardiocarpum, Carpodium, Collospermum, Coniferae, Coniferales, Cordaitopsida, Cornucarpus, Cupressoconus, Damudoxylon, Entylissa, Gondwanophyllites, Indoxylon, Kamthioxylon, Kaokoxylon, Kryshtofovichiella, Maheshwariella, Megaporoxylon, Nandorioxylon, Nidispermum, Niponophyllum, Nummulospermum, Otofeistia, Pakuriospermum, Palaeocarpus, Palispermum, Pantiaspermum, Paradoxospermum, Parapalaeoxylon, Platycardia, Polyloboxylon, Polysolenoxylon, Prototaxopitys, Prototaxoxylon, Pyriformispermum, Retortistoma, Rotundaspermum, Savitrispermum, Scirroma, Sclerospiroxylon, Sertostrobus, Shivacarpus, Sonajorispermum, Stephanostoma, Stereocarpus, Sujfunophyllum, Surangephyllum, Tanaidia, Tanaidocarpidium, Taxaliospermum, Taxineae, Taxopitys, Triangulospermum, Trigonomyelon, Uesuguipollenites, Voltziostrobus, Zalesskioxylon, Squamae, Ashmoripollis, Trisocladus, Embergerixylon, Parataxopitys, Yorkoxylon, Paradoxoxylon, Enzonalasporites, Lobatoxylon, Accintisporites, Falcisporites, Gnetaceaepollenites, Scotoxylon, Galeacornea, Minutosaccus, Lasiostrobus, Decussosporites, Sofrepites, Solenoxylon, Protopitys, Darneya, Shanbeipollenites, Dinophyton, Taxacites, Amdrupia, Tungussocarpus, Parcisporites, Cedripites, Perinopollenites, Majsassia, Antarcticoxylon, Yezonia, Pteridospermaexylon, Pilasporites, Cerebropollenites, Indusiisporites, Svalbardoxylon, Taeniopitys, Reticulopitys, Menaispermae, Pteridospermopsida, Striomonosaccites, Zonallapollenites, Protocircoporoxylon, Lagenospermopsida, Rugubivesiculites, Cycadinoxylon, Eddya, Protopolyporoxylon, Ktalenia, Exesipollenites, Tordoxylon, Prototaxodioxylon, Alisporites
Subtaxa: Hexapterospermales Lyginopteridales
Ecology: "photoautotroph"