Millerosteus is an extinct genus of coccosteid arthrodire placoderm from the Early Givetian stage of the Middle Devonian period. Fossils are found in Orkney and Caithness, Scotland. It was a small placoderm with a body length of 14cm (5.5in). Millerosteus is one of the few arthrodires known from specimens preserving the entire skeleton.

Phylogeny

Millerosteus is a member of the family Coccosteidae, which belongs to the clade Coccosteomorphi, one of the two major clades within Eubrachythoraci. The cladogram below shows the phylogeny of Millerosteus:

EubrachythoraciCoccosteomorphi Coccosteoidea Coccosteidae Millerosteus minor Coccosteus cuspidatus Dickosteus threiplandi Watsonosteus fletti Protitanichthys rockportensis Panxiosteidae Plourdosteus canadensis Panxiosteus ocullus Janiosteus timanicus Incisoscutoidea Harrytoombsia elegans Torosteus tuberculatus Torosteus pulchellus Mcnamaraspis kaprios Compagopiscis croucheri Trematosteus fontanellus Camuropiscidae Incisoscutum ritchiei Incisoscutum sarahae Rolfosteus canningensis Tubonasus lennardensis Fallacosteus turneri Camuropiscis laidlawi Latocamurus coulthardi Pachyosteomorphi
CoccosteomorphiCoccosteoidea Coccosteidae Millerosteus minor Coccosteus cuspidatus Dickosteus threiplandi Watsonosteus fletti Protitanichthys rockportensis Panxiosteidae Plourdosteus canadensis Panxiosteus ocullus Janiosteus timanicus Incisoscutoidea Harrytoombsia elegans Torosteus tuberculatus Torosteus pulchellus Mcnamaraspis kaprios Compagopiscis croucheri Trematosteus fontanellus Camuropiscidae Incisoscutum ritchiei Incisoscutum sarahae Rolfosteus canningensis Tubonasus lennardensis Fallacosteus turneri Camuropiscis laidlawi Latocamurus coulthardi
CoccosteoideaCoccosteidae Millerosteus minor Coccosteus cuspidatus Dickosteus threiplandi Watsonosteus fletti Protitanichthys rockportensis Panxiosteidae Plourdosteus canadensis Panxiosteus ocullus Janiosteus timanicus
CoccosteidaeMillerosteus minor Coccosteus cuspidatus Dickosteus threiplandi Watsonosteus fletti Protitanichthys rockportensis
Millerosteus minor Coccosteus cuspidatus
Millerosteus minor
Coccosteus cuspidatus
Dickosteus threiplandi Watsonosteus fletti Protitanichthys rockportensis
Dickosteus threiplandi
Watsonosteus fletti
Protitanichthys rockportensis
PanxiosteidaePlourdosteus canadensis Panxiosteus ocullus Janiosteus timanicus
Plourdosteus canadensis
Panxiosteus ocullus
Janiosteus timanicus
IncisoscutoideaHarrytoombsia elegans Torosteus tuberculatus Torosteus pulchellus Mcnamaraspis kaprios Compagopiscis croucheri Trematosteus fontanellus Camuropiscidae Incisoscutum ritchiei Incisoscutum sarahae Rolfosteus canningensis Tubonasus lennardensis Fallacosteus turneri Camuropiscis laidlawi Latocamurus coulthardi
Harrytoombsia elegans
Torosteus tuberculatus Torosteus pulchellus
Torosteus tuberculatus
Torosteus pulchellus
Mcnamaraspis kaprios Compagopiscis croucheri Trematosteus fontanellus Camuropiscidae Incisoscutum ritchiei Incisoscutum sarahae Rolfosteus canningensis Tubonasus lennardensis Fallacosteus turneri Camuropiscis laidlawi Latocamurus coulthardi
Mcnamaraspis kaprios
Compagopiscis croucheri Trematosteus fontanellus Camuropiscidae Incisoscutum ritchiei Incisoscutum sarahae Rolfosteus canningensis Tubonasus lennardensis Fallacosteus turneri Camuropiscis laidlawi Latocamurus coulthardi
Compagopiscis croucheri
Trematosteus fontanellus
CamuropiscidaeIncisoscutum ritchiei Incisoscutum sarahae Rolfosteus canningensis Tubonasus lennardensis Fallacosteus turneri Camuropiscis laidlawi Latocamurus coulthardi
Incisoscutum ritchiei Incisoscutum sarahae
Incisoscutum ritchiei
Incisoscutum sarahae
Rolfosteus canningensis Tubonasus lennardensis Fallacosteus turneri Camuropiscis laidlawi Latocamurus coulthardi
Rolfosteus canningensis
Tubonasus lennardensis Fallacosteus turneri Camuropiscis laidlawi Latocamurus coulthardi
Tubonasus lennardensis
Fallacosteus turneri Camuropiscis laidlawi Latocamurus coulthardi
Fallacosteus turneri
Camuropiscis laidlawi Latocamurus coulthardi
Camuropiscis laidlawi
Latocamurus coulthardi
Pachyosteomorphi