Mcnamaraspis Temporal range: Late Devonian: Frasnian, | |
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Artist's reconstruction of M. kaprios | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | † Placodermi |
Order: | † Arthrodira |
Suborder: | † Brachythoraci |
Clade: | † Eubrachythoraci |
Clade: | † Coccosteomorphi |
Superfamily: | † Incisoscutoidea |
Genus: | † Mcnamaraspis Long, 1995 |
Species | |
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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 (c. 380-375 million years ago). 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.
On 5 December 1995, the type species, M. kaprios, was officially proclaimed as the State Fossil emblem of Western Australia by the Governor of Western Australia, thus becoming the first official state fossil emblem for any state of Australia. [1] [2]
M. kaprios is an extinct marine fish that grew up to 0.5 m (1.6 ft) in length. With its large eyes, articulated jaw and sharp, razorlike dentition plates, it can be inferred that this midsize placoderm was an active predator that specialized in cracking through the shelled defenses of arthropods such as trilobites. It has a distinct cartilaginous snout not recorded in other placoderms. [1]
Mcnamaraspis was originally classified as a member of the family Plourdosteidae. [3] However, phylogenetic analysis later found Plourdosteidae to be an invalid grouping, and the family was dismissed. [4] [3] Mcnamaraspis is now considered to be a member of the superfamily Incisoscutoidea, which belongs to the clade Coccosteomorphi, one of the two major clades within Eubrachythoraci. The cladogram below shows the phylogeny of Mcnamaraspis: [5]
Eubrachythoraci |
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Dinichthys is an extinct monospecific genus of large marine arthrodire placoderm from the Late Devonian measuring around 3 metres (9.8 ft) long. Fossils were recovered from the Ohio Shale Formation along the Olentangy River in Delaware County, Ohio.
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.
Eastmanosteus is a fossil genus of dunkleosteid placoderms. It was closely related to the giant Dunkleosteus, but differed from that genus in size, in possessing a distinctive tuberculated bone ornament, a differently shaped nuchal plate and a more zig-zagging course of the sutures of the skull roof.
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 disproportionally large eye sockets. Researchers suggest it may have preyed on small mollusks.
Incisoscutum is an extinct genus of arthrodire placoderm from the Early Frasnian Gogo Reef, from Late Devonian Australia. The genus contains two species I. ritchiei, named after Alex Ritchie, a palaeoichthyologist and senior fellow of the Australian Museum, and I. sarahae, named after Sarah Long, daughter of its discoverer and describer, John A. Long.
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 specimen MNHM 2-177 measuring 37.5 cm (14.8 in) long.
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.
Xiangshuiosteus wui is an extinct monospecific genus of brachythoracid arthrodire placoderm from the Late Emsian stage of the Early Devonian epoch, discovered in Wuding County of Yunnan province, China. It has recently been reassessed as a dunkleosteid.
Harrytoombsia is an extinct genus of arthrodire placoderm from the Early Frasnian stage of the Late Devonian period. Fossils are found from Kimberley, Australia. It was a fast-swimming predator, and it had sharp blades of enamel-like material around the outer edge of the jaw for catching prey.
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.
Compagopiscis is an extinct genus of placoderm known from the Gogo Formation. It lived in the Upper Devonian of Western Australia. The genus is monotypic, with its only species being Compagopiscis croucheri.
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.
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.
Bullerichthys 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. It was thought to be durophagous, meaning that it preyed upon hard-shelled creatures such as mollusks.
Kendrickichthys 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. It was thought to be durophagous, meaning that it preyed upon hard-shelled creatures such as mollusks.