| Dicksonosteus Temporal range: | |
|---|---|
 | |
| D. arcticus fossil | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | † Placodermi |
| Order: | † Arthrodira |
| Clade: | † Phlyctaenioidei |
| Family: | † Phlyctaeniidae |
| Genus: | † Dicksonosteus Goujet, 1975 |
| Type species | |
| †Dicksonosteus arcticus Goujet, 1975 | |
Dicksonosteus is an extinct genus of basal arthrodire placoderm fish which lived during the Early Devonian period of Spitsbergen, Norway. [1]
Within Arthrodira, Dicksonosteus is considered a member of "Phylctaenii", a paraphyletic grouping within the clade Phlyctaenioidei, basal to the suborder Brachythoraci. [1] [2] Dicksonosteus was once considered an actinolepid, but is now grouped within the family Phlyctaeniidae. [3] Dicksonosteus is most closely related to Arctolepis and Heintzosteus . [2]
Dicksonosteus is considered basal to the arthrodires, the most successful and widespread group of placoderms during the Devonian period notable for the movable joint between the armour sections surrounding their heads and bodies. Its body is wide and flat, and unlike the more robust-jawed arthrodires that would come after it, such as Dunkleosteus and Coccosteus , its jaws were relatively feeble, suggesting the lifestyle of a benthic fish that subsisted primarily on smaller, softer-bodied animals. Exceptionally preserved fossil specimens of Dicksonosteus from Spitsbergen, Norway display details of its braincase and internal anatomy, the details of which have been described.How?
Arthrodira is an order of extinct armored, jawed fishes of the class Placodermi that flourished in the Devonian period before their sudden extinction, surviving for about 50 million years and penetrating most marine ecological niches. Arthrodires were the largest and most diverse of all groups of placoderms.
Brachythoraci is an extinct suborder of arthrodire placoderms, armored fish most diverse during the Devonian.
Rolfosteus is an extinct monospecific genus of arthrodire placoderm from the Early Frasnian stage of the Late Devonian period, found at the Gogo Formation of Western Australia.
Heintzosteus is an extinct genus of placoderm arthrodire fish, which lived during the Late Devonian period in Spitsbergen, Norway.
Bruntonichthys is an extinct monospecific genus of arthrodire placoderm from the Early Frasnian stage of the Late Devonian period. Fossils are found in the Gogo Formation of the Kimberley region of Australia. The skull is about 139 millimetres long, and had proportionally large eye sockets. Researchers suggest it may have preyed on small mollusks.
Plourdosteus is an extinct genus of placoderm arthrodire which was relatively widespread in Euramerica during the Givetian to Frasnian ages of the Devonian. It was a small placoderm, with P. canadensis measuring 37.5–51.4 cm (14.8–20.2 in) long.
Mcnamaraspis is an extinct monospecific genus of arthrodire placoderm that inhabited the ancient reef system of north Western Australia during the Frasnian epoch of the Late Devonian period. The type specimen was found and described by John A. Long from the Gogo Formation near Fitzroy Crossing. This fossil fish showed new anatomical features in arthrodires, like the well-preserved annular (ring-shaped) cartilages of the snout, previously inferred to be present by Erik Stensiö of Sweden. It is occasionally referred to as "The Gogo Fish" after the locale the holotype was excavated from.
Camuropiscidae is a family of mostly small, bullet or spindle-shaped extinct arthrodire placoderms from the Late Devonian. With the exception of the snub-nosed Simosteus, camuropiscid placoderms are characterized by an elongated, tubular snout. The entire family is restricted to the Frasnian Gogo Reef Formation of Australia.
Fallacosteus is an extinct monospecific genus of arthrodire placoderm from the Early Frasnian stage of the Late Devonian period, found at the Gogo Formation of Kimberley, Western Australia. As with almost all other camuropiscids, F. turneri had an elongated snout that may have enhanced its hydrodynamic streamlining.
Camuropiscis is an extinct genus of arthrodire placoderm from the Early Frasnian stage of the Late Devonian period, found at the Gogo Formation of Kimberley, Western Australia. The species of Camuropiscis had a flattened, elongated snout that may have aided in enhancing its hydrodynamic streamlining.
Tubonasus is an extinct monospecific genus of long-snouted arthrodire placoderm from the Early Frasnian stage of the Late Devonian period, found at the Gogo Formation of Kimberley, Western Australia.
Latocamurus is an extinct monospecific genus of flat-nosed arthrodire placoderm from the Early Frasnian stage of the Late Devonian period, found at the Gogo Formation of Kimberley, Western Australia.
Dunkleosteoidea is an extinct superfamily of arthrodire placoderms that lived during the Devonian period. The gigantic apex predator Dunkleosteus terrelli is the best known member of this group.
Eubrachythoraci is an extinct clade of arthrodire placoderms within the suborder Brachythoraci, armored fish most diverse during the Devonian. Most are considered to be pelagic long-distance swimmers, leading to their widespread distribution beginning from at least the Middle Devonian period.
Pachyosteomorphi is an extinct clade of arthrodire placoderms within the Eubrachythoraci, armored fish most diverse during the Devonian. Most are considered to be pelagic long-distance swimmers, leading to their widespread distribution beginning from at least the Middle Devonian period.
Coccosteomorphi is an extinct clade of arthrodire placoderms within the Eubrachythoraci, armored fish most diverse during the Devonian. Most are considered to be pelagic long-distance swimmers, leading to their widespread distribution beginning from at least the Middle Devonian period.
Millerosteus is an extinct genus of coccosteid arthrodire placoderm from the Early Givetian stage of the Middle Devonian period. Fossils are found in the Orkneys and Caithness, Scotland. It was a small placoderm with an body length of 14 cm (5.5 in). Millerosteus is one of the few arthrodires known from specimens preserving the entire skeleton.
Dickosteus is an extinct genus of coccosteid arthrodire placoderm from the Late Eifelian to Early Givetian stages of the Middle Devonian period. Fossils are found in the Orkneys and Caithness, Scotland. It was a small placoderm with a total body length of 43.7–52.3 cm (17.2–20.6 in). It is one of the few placoderms for which complete bodies are known.
Watsonosteus is an extinct genus of coccosteid arthrodire placoderm from the Late Givetian stage of the Middle Devonian period. Fossils are found in the Orkney Islands, Scotland. It was a small placoderm with an total body length of 57 cm (22 in), with the largest individuals reaching lengths of 1 m (39 in). It is one of the few arthrodires for which complete body fossils are known.
Torosteus is an extinct genus of arthrodire placoderm from the Early Frasnian stage of the Late Devonian period. Fossils are found in the Kimberley region of Australia.
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