Pachyosteus

Last updated

Pachyosteus
Temporal range: Late Devonian, 382.7–359.3  Ma
Pachyosteus bulla reconstruction.jpg
Artist's reconstruction
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Placodermi
Order: Arthrodira
Suborder: Brachythoraci
Clade: Eubrachythoraci
Clade: Pachyosteomorphi
Clade: Aspinothoracidi
Family: Selenosteidae
Genus: Pachyosteus
Jaekel, 1903
Species
  • Pachyosteus bullaJaekel, 1903 (type)
Synonyms
Fossil on display at Geological Museum of the State Geological Institute in Warsaw, Poland Pachyosteus bulla.jpg
Fossil on display at Geological Museum of the State Geological Institute in Warsaw, Poland

Pachyosteus is an extinct monospecific genus of medium-sized selenosteid arthrodire placoderm known from the Upper Frasnian Kellwasserkalk facies of Late Devonian Bad Wildungen, Germany and from the Famennian portions of the Holy Cross Mountains of Poland. [1] The type species Pachyosteus bulla has a broad skull about 7 to 10 centimetres (3 to 4 in) long, a comparatively long median dorsal plate, and a short rostral plate that meets the pineal plate.

Phylogeny

Pachyosteus is a member of the family Selenosteidae of the clade Aspinothoracidi, which belongs to the clade Pachyosteomorphi, one of the two major clades within Eubrachythoraci. The cladogram below shows the phylogeny of Pachyosteus: [2]

Eubrachythoraci  

Coccosteomorphi

  Pachyosteomorphi  

Rhachiosteus pterygiatus

Dunkleosteoidea  

Eastmanosteus calliaspis

Eastmanosteus pustulosus

Kiangyousteus yohii

Golshanichthys asiatica

Westralichthys uwagedensis

Dunkleosteus raveri

Dunkleosteus terrelli

Dunkleosteus amblyodoratus

  Heterostiidae  

Heterosteus ingens

Yinosteus major

Aspinothoracidi

Tapinosteus heintzi

Bullerichthys fascidens

Kendrickichthys cavernosus

Bruntonichthys multidens

Dinichthys herzeri

Hadrosteus rapax

Gorgonichthys clarki

  Selenosteidae  

Heintzichthys gouldii

Pachyosteus bulla

Gymnotrachelus hydei

Stenosteus angustopectus

Brachyosteus dietrichi

Melanosteus occitanus

Rhinosteus parvulus

In his cladogram, Rücklin (2011) regards Pachyosteus bulla as a basal selenosteid, being the sister taxon of the American genera, and the Kellwasserkalk genera of Germany and Morocco. [3]

Aspinothoracidi

Parabelosteus

Brachydeirus

Selenosteidae

Pachyosteus

Selenosteus

Stenosteus

Gymnotrachelus

Microsteus

Walterosteus

Draconichthys

Enseosteus

Melanosteus

Rhinosteus

Related Research Articles

Dunkleosteidae Extinct family of fishes

Dunkleosteidae is an extinct family of arthrodire placoderms that lived during the Devonian period. The gigantic apex predator Dunkleosteus terrelli is the best known member of this group.

<i>Rolfosteus</i>

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.

<i>Eastmanosteus</i>

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.

<i>Mcnamaraspis</i>

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.

Selenosteidae

Selenosteidae is an extinct family of small to large-sized arthrodire placoderms from the Late Devonian. With the exception of the Chinese Phymosteus, selenosteids lived in shallow seas in what is now Eastern North America, Eastern Europe, and Northeastern Africa.

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.

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

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.

<i>Tubonasus</i>

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.

<i>Draconichthys</i>

Draconichthys elegans a selenosteid arthrodire placoderm from the Late Frasnian Kellwasserkalk facies of the Anti-Atlas Mountains of what is now Morocco. During the Late Devonian, the region would have been a shallow, algae-dimmed sea.

<i>Hadrosteus</i>

Hadrosteus is an extinct monospecific genus of large arthrodire placoderm from the Late Frasnian Kellwasserkalk facies of Bad Wildungen, Germany. It had large, double-pronged inferognathals, and serrated edges along its mandible, strongly suggesting that it was a fish-eating predator. The head had a triangular snout, and the trunkshield was short, but high, with a median dorsal plate that was broader than wide. The average skull length is about 16 centimeters.

<i>Stenosteus</i> Genus of fishes (fossil)

Stenosteus is an extinct monospecific genus of medium-sized selenosteid arthrodire placoderms of the Late Devonian period known from the Upper Famennian Cleveland Shale of Ohio. Estimated skull lengths range from 6 to 9 centimeters Most fossils of Stenosteus have been scraps of armor and portions of tooth-plates suggestive of Selenosteus. In 1996, enough material of a new species, S. angustopectus, was recovered to allow a reconstruction of armor that resembles that of Selenosteus.

<i>Gymnotrachelus</i> Genus of fishes (fossil)

Gymnotrachelus is an extinct monospecific genus of large selenosteid arthrodire placoderm of the Late Devonian known from the Late Famennian Cleveland Shale of Ohio. The type species Gymnotrachelus hydei was originally reconstructed as physically resembling Selenosteus, with slightly smaller orbits. Later specimens led to a reappraisal, and now G. hydei is thought to have a more gar-like or barracuda-like build.

<i>Microsteus</i>

Microsteus is an extinct genus of small selenosteid arthrodire placoderms known from the Upper Frasnian Kellwasserkalk facies of Late Devonian Germany.

<i>Enseosteus</i>

Enseosteus is an extinct genus of small selenosteid arthrodire placoderms known from the Upper Frasnian Kellwasserkalk facies of Late Devonian Germany and Morocco.

<i>Rhinosteus</i> Genus of fishes (fossil)

Rhinosteus is an extinct genus of small to medium selenosteid arthrodire placoderms of the Late Devonian known from the Upper Frasnian Kellwasserkalk facies of Bad Wildungen, Germany and Morocco.

<i>Melanosteus</i> Genus of fishes (fossil)

Melanosteus is an extinct genus of small selenosteid arthrodire placoderms of the Late Devonian period known from the Upper Frasnian Montagne Noire of Southern France. Rücklin (2011) regards Melanosteus as the sister taxon of Rhinosteus. During the Frasnian stage, Melanosteus occitanus lived off the coast of an island continent, "Armorica," which consisted of portions of what would become Southern France.

<i>Braunosteus</i>

Braunosteus schmidti is a medium-sized selenosteid arthrodire placoderm known from the Upper Frasnian Kellwasserkalk facies of Late Devonian Bad Wildungen, Germany. B. schmidti has a broad skull about 9 centimeters long, and a short, but pointed rostrum. Its appearance is very similar to that of the basal selenosteid Pachyosteus.

<i>Walterosteus</i>

Walterosteus is an extinct genus of small selenosteid arthrodire placoderms known from the Upper Frasnian Kellwasserkalk facies of Late Devonian Germany and Morocco.

Compagopiscis is an extinct genus of placoderm known from the Gogo Formation. It lived in the Upper Devonian of Western Australia. Compagopiscis is one of the earliest known vertebrates to have teeth. The genus is monotypic, with its only species being Compagopiscis croucheri.

Tapinosteus is an extinct monospecific genus of arthrodire placoderm from the Late Frasnian stage of the Late Devonian period. Fossils are found from Bad Wildungen, Germany.

References

  1. Denison, Robert (1978). Handbook of Paleoichthyology, Volume 2, Placodermi. New York: Gustav Fischer Verlage. p. 94. ISBN   9780895740274.
  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.
  3. RÜCKLIN, MARTIN (January 14, 2011). "First selenosteid placoderms from the eastern Anti-Atlas of Morocco; osteology, phylogeny and palaeogeographical implications". Palaeontology. 56 (1): 25–62. doi:10.1111/j.1475-4983.2010.01026.x.