| Mcnamaraspis | |
|---|---|
 | |
| Artist's reconstruction ofM. 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 anextinctmonospecificgenus ofarthrodireplacoderm that inhabited the ancient reef system of northWestern Australia during theFrasnian epoch of theLate Devonian period (c. 380-375 million years ago). Thetype specimen was found and described byJohn A. Long from theGogo Formation nearFitzroy 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 byErik Stensiö of Sweden. It is occasionally referred to as "The Gogo Fish" after the locale theholotype was excavated from.
On 5 December 1995, thetype species,M. kaprios, was officially proclaimed as theState Fossil emblem ofWestern Australia by theGovernor 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 astrilobites. It has a distinct cartilaginous snout not recorded in other placoderms.[1]
Mcnamaraspis was originally classified as a member of thefamilyPlourdosteidae.[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 thesuperfamilyIncisoscutoidea, which belongs to thecladeCoccosteomorphi, one of the two major clades withinEubrachythoraci. Thecladogram below shows thephylogeny ofMcnamaraspis:[5]
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