Rolfosteus

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Rolfosteus
Temporal range: Late Devonian: Frasnian, 382.7–372.2  Ma
Rolfosteus canningensis.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Placodermi
Order: Arthrodira
Suborder: Brachythoraci
Clade: Eubrachythoraci
Clade: Coccosteomorphi
Superfamily: Incisoscutoidea
Family: Camuropiscidae
Genus: Rolfosteus
Dennis and Miles, 1979
Species
  • Rolfosteus canningensisDennis and Miles, 1979

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. [1]

Contents

Description

Rolfosteus had a skull reaching 11.5 centimetres (4.5 in), [1] with tough plating on the front of its body. Like other arthrodires, such as Coccosteus and the giant Dunkleosteus , it had sharp, bony plates on its mouth which formed a turtle-like beak for cutting prey to pieces. Rolfosteus's most unusual feature was its highly elongated rostrum (snout), which may have been used to enhance its sense of smell as well as increase its hydrodynamic streamlining, making it well adapted to be a pelagic pursuit predator. Its fast jaw movement and jaw morphology allowed it to effectively capture prey and swallow them whole. [2]

Phylogeny

Rolfosteus is a member of the family Camuropiscidae under the superfamily Incisoscutoidea, which belongs to the clade Coccosteomorphi, one of the two major clades within Eubrachythoraci. [3] [4] The cladogram below shows the phylogeny of Rolfosteus: [4]

Eubrachythoraci  
  Coccosteomorphi
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

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<i>Bruntonichthys</i> Extinct genus of fishes

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.

<i>Mcnamaraspis</i>

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<i>Fallacosteus</i> Species of extinct placoderm

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<i>Camuropiscis</i>

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.

<i>Tubonasus</i>

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<span class="mw-page-title-main">Dunkleosteoidea</span> Extinct superfamily of fishes

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<i>Harrytoombsia</i> Extinct genus of arthrodire placoderm

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.

<span class="mw-page-title-main">Eubrachythoraci</span> Extinct suborder of fishes

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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.

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Panxiosteus is an extinct monospecific genus of placoderm arthrodire from the Middle Devonian: Givetian stage of Yunnan province, China.

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<span class="mw-page-title-main">Coccosteomorphi</span> Extinct suborder of fishes

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.

References

  1. 1 2 Dennis, Kim; Miles, R. S. (December 1979). "Eubrachythoracid arthrodires with tubular rostral plates from Gogo, Western Australia". Zoological Journal of the Linnean Society . 67 (4): 297–328. doi:10.1111/j.1096-3642.1979.tb01118.x. ISSN   0024-4082.
  2. Trinajstic, Kate; Briggs, Derek E. G.; Long, John A. (23 November 2021). "The Gogo Formation Lagerstätte: a view of Australia's first great barrier reef". Journal of the Geological Society . 179 (1). doi: 10.1144/jgs2021-105 . ISSN   0016-7649.
  3. You-An Zhu; Min Zhu (2013). "A redescription of Kiangyousteus yohii (Arthrodira: Eubrachythoraci) from the Middle Devonian of China, with remarks on the systematics of the Eubrachythoraci". Zoological Journal of the Linnean Society . 169 (4): 798–819. doi: 10.1111/zoj12089 .
  4. 1 2 Zhu, You-An; Zhu, Min; Wang, Jun-Qing (1 April 2016). "Redescription of Yinostius major (Arthrodira: Heterostiidae) from the Lower Devonian of China, and the interrelationships of Brachythoraci". Zoological Journal of the Linnean Society . 176 (4): 806–834. doi: 10.1111/zoj.12356 . ISSN   0024-4082.

Further reading