Exutaspis

Exutaspis megista is an extinct, "giant" buchanosteid arthrodire placoderm. Its fossils have been found in the Late Emsian-aged marine strata of the Jiucheng and Haikou Formations in Wuding, Yunnan.

It was originally described as a phlyctaeniid. Later, after comparison with the Chinese Buchanosteus guanxianesis, Exutaspis was reappraised as a buchanosteid. The holotype, a "head roof," is 21 cm (8.3 in) long.

References

Placoderms
Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Infraphylum: Gnathostomata
Major clades Acanthothoraci Antiarchi Arthrodira Petalichthyida Phlyctaeniida Phyllolepida Ptyctodontida Rhenanida
Basal placoderms Acanthothoraci* ?Hagiangellidae ?Hagiangella Palaeacanthaspidae* Arabosteus Dobrowlania Kimaspis Kolymaspis Kosoraspis Palaeacanthaspis Radotina Romundina ?Weejasperaspididae Weejasperaspis Murrindalaspis Rhenanida Asterosteus Bolivosteus Gemuendina Jagorina Nefudina Ohioaspis Others Brindabellaspis Pseudopetalichthys Stensioella Entelognathus
Antiarchi Basal antiarchs Minicrania Silurolepis Sinolepidae Dayaoshania Grenfellaspis Sinolepis Vanchienolepis Xichonolepis Yunnanolepiformes incertae sedis Heteroyunnanolepis Zhanjilepis Shimenolepis Chuchinolepidae Chuchinolepis Yunnanolepididae Parayunnanolepis Phymolepis Mizia Yunnanolepis Euantiarcha Asterolepidoidei Asperaspis Asterolepis Byssacanthus Gerdalepis Grossaspis Hunanolepis Kirgisolepis Pambulaspis Pterichthyodes Remigolepis Sherbonaspis Stegolepis Bothriolepidoidei Dianolepis Kirgisolepis Luquanolepis Nawagiaspis Tenizolepis Bothriolepididae Bothriolepis Briagalepis Grossilepis Monarolepis Vietnamaspis Jiangxilepididae Jiangxilepis Ningxialepis Microbrachiidae Hohsienolepis Microbrachius Wudinolepis
Petalichthyida Basal and incertae sedis Diandongpetalichthys Neopetalichthys Quasipetalichthyidae Quasipetalichthys Eurycaraspis Macropetalichthyidae Ellopetalichthys Epipetalichthys Lunaspis Macropetalichthys Notopetalichthys Shearsbyaspis Tongdzuylepis Wijdeaspis
Ptyctodontida Ptyctodontidae Austroptyctodus Campbellodus Chelyophorus Ctenurella Denisonodus Destnoporella Eczematolepis Goniosteus Materpiscis Palaeomylus Ptyctodopis Ptyctodus Rhamphodopsis Rhynchodus
Arthrodira Actinolepidoidei* Aethaspis Aleosteus Anarthraspis Baringaspis Bryantolepis Erikaspis Eskimaspis Heightingtonaspis Kujdanowiaspis Lataspis Lehmanosteus Mediaspis Proaethaspis Sigaspis Simblaspis Actinolepidae* Actinolepis Ailuracantha Bollandaspis Szeaspis Antarctaspidae* Antarctaspis Qataraspis Yujiangolepis Phyllolepida Austrophyllolepis Cowralepis Gavinaspis Phyllolepis Placolepis Wuttagoonaspidae Wuttagoonaspis Yiminaspis Phlyctaenioidei / Phlyctaenii* Phlyctaenididae Aggeraspis Cartieraspis Diadsomaspis Elegantaspis Neophlyctaenius Pageauaspis Phlyctaenius Arctaspididae Dicksonosteus Arctolepididae Arctolepis Heintzosteus Huginaspis Kueichowlepis Groenlandaspididae Africanaspis Boomeraspis Groenlandaspis Mithakaspis Mulgaspis Tiaraspis Turrisaspis Williamsaspididae Elvaspis Williamsaspis Brachythoraci Basal brachythoracids Antineosteus Gemuendenaspis Maideria Xiangshuiosteus Heterosteidae Herasmius Heterosteus Tollichthys Holonematidae Artesonema Belemnacanthus Bimbianga Deirosteus Deveonema Gyroplacosteus Holonema Megaloplax Rhenonema Tropidosteus Tropinema Homosteidae Angarichthys Cathlesichthys Dhanguura Euleptaspis Euleptaspis Luetkeichthys Migmatocephala Antineosteus Atlantidosteus Homosteus Taemasosteus Tityosteus Buchanosteidae Arenipiscis Buchanosteus Burrinjucosteus Errolosteus Goodradigbeeon Parabuchanosteus Toombsosteus Uralosteus Eubrachythoraci Coccosteomorphi Camuropiscidae Camuropiscis Fallacosteus Latocamurus Simosteus Rolfosteus Tubonasus Coccosteidae Belgiosteus Clarkeosteus Coccosteus Dickosteus Jiuchengia Livosteus Millerosteus Protitanichthys Watsonosteus Incisoscutidae Incisoscutum Plourdosteidae Compagopiscis Gogopiscis ?Kimberleyichthys Menamaraspis ?Plourdosteus Torosteidae Eldenosteus Harrytoombsia Torosteus Pachyosteomorphi Kiangyousteus Brachydeiridae Brachydeirus Oxyosteus Synauchenia Leptosteidae Leptosteus Rachiosteidae Rachiosteus Aspinothoracidi Bungartiidae Bungartius Dinichthyidae* Bruntonichthys Bullerichthys Dinichthys Kianyousteus Protitanichthys Squamatognathus Hadrosteidae Hadrosteus Leiosteidae Erromenosteus Mylostomatidae Dinomylostoma Kendrickichthys Mylostoma Tafilalichthys Selenosteidae Braunosteus Draconichthys Enseosteus Gymnotrachelus Melanosteus Microsteus Pachyosteus Paramylostoma Phymosteus Rhinosteus Selenosteus Stenosteus Walterosteus Titanichthyidae Titanichthys Trematosteidae Belosteus Brachyosteus Cyrtosteus Parabelosteus Trematosteus Dunkleosteoidea Panxiosteidae Janiosteus ?Kimberleyichthys Panxiosteus ?Plourdosteus Dunkleosteidae Dunkleosteus Eastmanosteus Golshanichthys Hussakofia Westralichthys
Related categories Placoderms Devonian fish