Cephalaspis: Difference between revisions

Cephalaspis; Temporal range: Early Devonian (Lochkovian to Emsian), 415–398 Ma PreꞒ Ꞓ O S D C P T J K Pg N
	Digital recreation of Cephalaspis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	†Osteostraci
Genus:	†Cephalaspis; Agassiz, 1835
Species:	†C. lyelli
Binomial name
	†Cephalaspis lyelli; Agassiz, 1835

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Cephalaspis (from Greek: κεφαλή kephalḗ, 'head' and Greek: ἀσπίς aspís, 'shield') is a possibly monotypic genus of extinct osteostracan agnathan vertebrate. It was a trout-sized detritivorous fish that lived in the early Devonian.

Description

Like its relatives, Cephalaspis was heavily armored, presumably to defend against predatory placoderms and eurypterids, as well as to serve as a source of calcium for metabolic functions in calcium-poor freshwater environments. It had sensory patches along the rim and center of its head shield, which were used to sense for worms and other burrowing organisms in the mud.^{[citation needed]}

Diet

Because its mouth was situated directly beneath its head, Cephalaspis was thought of as being a bottom-feeder, akin to a heavily armoured catfish or sturgeon. It moved its plow-like head from side to side, Cephalaspis easily stirring sand and dust into the water, along with revealing the hiding places of its prey, digging up worms or crustaceans hidden in the mud and algae, as well as sifting through detritus (inferred from its lack of jaws and inability to bite).^[2]

Classification

The genus Cephalaspis has long been used as a wastebasket taxon since Agassiz erected it in 1835 for four species, C. lyelli, C. rostratus, C. lewisi and C. lloydi.^[3] Later, it was eventually determined that the last three species were portions of what would eventually be described as the heterostracan Pteraspis rostratus. C. lyelli, named after Sir Charles Lyell,^[3] would be left to be the type species of the genus. Other researchers would continue adding other similar-looking osteostracans throughout the decades until, in 2009, Sansom reevaluated Osteostraci, and determined that only C. lyelli could be reliably placed within Cephalaspis, and that probably all other species would eventually need to be reexamined and be placed into other genera.^[4] In the same 2009 study, Sansom also determined that Cephalaspis sensu stricto was the sister-taxon of cornuate osteostracans, i.e., all osteostracans that either have, or have ancestors that had defined corners on the head-shields.^[4]

Included species

The following is a list of species that have been included into Cephalaspis; most likely do not belong to the genus, but have not been formally moved.^[5]^[6]

†Cephalaspis lyelli (Agassiz, 1835) (type species)
†"Cephalaspis" aarhusi (Wangsjö, 1952)
†"Cephalaspis" agassizi (Lankester, 1868)
†"Cephalaspis" brevirostris (Denison, 1952)
†"Cephalaspis" broughi (Wangsjö, 1952)
†Cephalaspis cradleyensis (Stensiö, 1932)
†"Cephalaspis" dissimulata (Wangsjö, 1952)
†"Cephalaspis" doryphorus (Wangsjö, 1952)
†"Cephalaspis" fletti (Stensiö, 1932)
†"Cephalaspis" fraticornis (Wangsjö, 1952)
†"Cephalaspis" hyperboreus (Wangsjö, 1952)
†"Cephalaspis" lankestri (Stensiö, 1932)
†"Cephalaspis" lornensis (Traquair, 1899)
†"Cephalaspis" microlepidota (Balabai, 1962)
†"Cephalaspis" novaescotiae (Denison, 1955)
†"Cephalaspis" platycephalus (Wangsjö, 1952)
†"Cephalaspis" producta (Wangsjö, 1952)
†"Cephalaspis" recticornis (Wangsjö, 1952)
†"Cephalaspis" spinifer (Stensiö, 1923)
†"Cephalaspis" tenuicornis (Wangsjö, 1952)
†"Cephalaspis" verrulosa (Wangsjö, 1952)
†"Cephalaspis" websteri (Stensiö, 1932)
†"Cephalaspis" whitbachensis (Stensiö, 1932)
†"Cephalaspis" wyomingensis (Denison, 1952)

Species of Cephalaspis that have been reassigned

†Cephalaspis corystis (Wangsjö, 1952) = Machairaspis corystis
†Cephalaspis excellens (Wangsjö, 1952) = Waengsjoeaspis excellens
†Cephalaspis elegans (Balabai, 1962)^[7] = Zychaspis siemiradzkii^[8]
†Cephalaspis hastata (Wangsjö, 1952) = Machairaspis hastata
†Cephalaspis hoeli (Stensiö, 1927) = Mimetaspis hoeli
†Cephalaspis ibex (Wangsjö, 1952) = Machairaspis ibex
†Cephalaspis jarviki (Wangsjö, 1952) = Diademaspis jarviki
†Cephalaspis magnifica (Traquair, 1893) = Trewinia magnifica
†Cephalaspis microtuberculata (Obruchev, 1961) = Escuminaspis laticeps
†Cephalaspis pagei (Lankester, 1868) = Janaspis pagei
†Cephalaspis patteni (Robertson, 1936) = Levesquaspis patteni
†Cephalaspis powriei (Lankester, 1868) = Janaspis powriei
†Cephalaspis rosamundae (Roberts, 1937) = Escuminaspis laticeps
†Cephalaspis rostrata (Agassiz, 1835) = Pteraspis rostrata
†Cephalaspis salweyi (Egerton, 1857) = Zenaspis salweyi
†Cephalaspis utahensis (Branson & Mehl, 1931) = Camptaspis utahensis

Other miscellaneous species once assigned to Cephalaspis

†Cephalaspis abergavenniensis (White, 1963)
†Cephalaspis acuticornis (Stensiö, 1927)
†Cephalaspis billcrofti (White & Toombs, 1983)
†Cephalaspis campbelltonensis (Whiteaves, 1881)
†Cephalaspis cocculi (MacGillivray, 1921)
†Cephalaspis cwmmillensis (White & Toombs, 1983)
†Cephalaspis dawsoni (Lankester, 1870)
†Cephalaspis djurinensis (Balabai, 1962)
†Cephalaspis grabrielsei (Dineley & Loeffler, ?)
†Cephalaspis isachseni (Stensiö, 1927)
†Cephalaspis jexi (Traquair, 1893)
†Cephalaspis peninsula (Pageau, 1969)
†Cephalaspis schrenckii (Pander, ?)
†Cephalaspis sp. "Forfar" (Trewin & Davidson, 1996)
†Cephalaspis syndenhami (Pageau, 1969)
†Cephalaspis traquairi (Stensio, ?)
†Cephalaspis uternaria (?)
†Cephalaspis vogti (Stensiö, 1927)
†Cephalaspis watneliei (Stensiö, 1927)
†Cephalaspis westolli (Russell, 1954)

References

^ L. Agassiz. 1835. Recherches Sur Les Poissons Fossiles. Tome I (livr. 18).
^ Haines, Tim; Chambers, Paul (2005). The complete guide to prehistoric life. Buffalo, N.Y.: Firefly Books. p. 23. ISBN 978-1-55407-181-4.
^ ^a ^b White, E. I. "On Cephalaspis lyelli Agassiz." Palaeontology 1.2 (1958): 99-105. [1] Archived 2015-10-19 at the Wayback Machine
^ ^a ^b Sansom, Robert S. "Phylogeny, classification and character polarity of the Osteostraci (Vertebrata)." Journal of Systematic Palaeontology 7.1 (2009): 95-115. [2]
^ Groh, S. "Appendix" (PDF). Patterns of diversification in osteostracan evolution (M.S.). Uppsala University.
^ cephalaspidomorphi at users.atw.hu/fishindex
^ On the cephalaspid fauna of the Podolian plateau. PP Balabai - aukovi zapysky Naukovo-pryodo-znavcogomuzeâ AN URSR, L'vov, 1962
^ Preliminary description of Lower Devonian Osteostraci from Podolia (Ukrainian S.S.R.). P Janvier, Bulletin of the British Museum (Natural History) Geology 38(5) pages 309--334 (1985)

Janvier, P (1996) Early Vertebrates Oxford University Press;
Donoghue and Smith (2001) The anatomy of Turinia pagei (Powrie), and the phylogenetic status of the Thelodonti, Transactions of the Royal Society of Edinburgh: Earth Sciences, 92, p. 15-37

External links

Paleos Vertebrates [3]
"Cephalaspis". Fossilworks. Gateway to the Paleobiology Database. Retrieved 3 January 2017.

[1] L. Agassiz. 1835. Recherches Sur Les Poissons Fossiles. Tome I (livr. 18).

[comguide-2] Haines, Tim; Chambers, Paul (2005). The complete guide to prehistoric life. Buffalo, N.Y.: Firefly Books. p. 23. ISBN 978-1-55407-181-4.

[white-3] White, E. I. "On Cephalaspis lyelli Agassiz." Palaeontology 1.2 (1958): 99-105. [1] Archived 2015-10-19 at the Wayback Machine

[sansom-4] Sansom, Robert S. "Phylogeny, classification and character polarity of the Osteostraci (Vertebrata)." Journal of Systematic Palaeontology 7.1 (2009): 95-115. [2]

[groh-5] Groh, S. "Appendix" (PDF). Patterns of diversification in osteostracan evolution (M.S.). Uppsala University.

[6] spidomorphi at users.atw.hu/fishindex

[7] On the cephalaspid fauna of the Podolian plateau. PP Balabai - aukovi zapysky Naukovo-pryodo-znavcogomuzeâ AN URSR, L'vov, 1962

[8] Preliminary description of Lower Devonian Osteostraci from Podolia (Ukrainian S.S.R.). P Janvier, Bulletin of the British Museum (Natural History) Geology 38(5) pages 309--334 (1985)

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@@ Line 1: / Line 1: @@
+{{Short description|Genus of extinct jawless fish}}
-{{Refimprove|paleontology-related article|date=October 2011}}
+{{More citations needed|paleontology-related article|date=October 2011}}
 {{speciesbox
 | name = ''Cephalaspis''
-| fossil_range = Early [[Devonian]] {{fossil range|415|398}}
+| fossil_range = [[Early Devonian]] ([[Lochkovian]] to	[[Emsian]]), {{fossil range|415|398}}
 | image = Ostracoderm digital recreation..jpg
 | image_caption = Digital recreation of ''Cephalaspis''
 | genus = Cephalaspis
-| parent_authority = Agassiz, 1835<ref> L. Agassiz. 1835. Recherches Sur Les Poissons Fossiles. Tome I (livr. 18).</ref>
+| parent_authority = Agassiz, 1835<ref>L. Agassiz. 1835. Recherches Sur Les Poissons Fossiles. Tome I (livr. 18).</ref>
 | species = lyelli
 | authority = Agassiz, 1835
 }}
-'''''Cephalaspis''''' (meaning "head shield") is a probably [[monotypic taxon|monotypic]] [[Genus (biology)|genus]] of extinct [[Osteostraci|osteostracan]] [[agnatha]]n [[vertebrate]]. It was a trout-sized [[detritivorous]] fish that lived in estuaries of the early [[Devonian]].
+'''''Cephalaspis''''' (from {{lang-el|κεφαλή}} {{transl|el|kephalḗ}}, 'head' and {{lang-el|ἀσπίς}} {{transl|el|aspís}}, 'shield') is a possibly [[monotypic taxon|monotypic]] [[Genus (biology)|genus]] of extinct [[Osteostraci|osteostracan]] [[agnatha]]n [[vertebrate]]. It was a trout-sized [[detritivorous]] fish that lived in the early [[Devonian]].
 ==Description==
-Like its relatives, ''Cephalaspis'' was heavily armored, presumedly to defend against predatory [[placoderm]]s and [[eurypterid]]s, as well as to serve as a source of calcium for metabolic functions in calcium-poor freshwater environments.{{cn|date=December 2016}} It had sensory patches along the rim and center of its head shield, which were used to sense for worms and other burrowing organisms in the mud.
+Like its relatives, ''Cephalaspis'' was heavily armored, presumably to defend against predatory [[placoderm]]s and [[eurypterid]]s, as well as to serve as a source of calcium for metabolic functions in calcium-poor freshwater environments. It had sensory patches along the rim and center of its head shield, which were used to sense for worms and other burrowing organisms in the mud.{{citation needed|date=December 2016}}
 ===Diet===
@@ Line 20: / Line 21: @@
 ==Classification==
-The genus ''Cephalaspis'' has long been used as a [[wastebasket taxon]] since [[Louis Agassiz|Agassiz]] erected it in 1835 for four species, ''C. lyelli'', ''C. rostratus'', ''C. lewisi'' and ''C. lloydi''.<ref name= white>White, E. I. "On ''Cephalaspis lyelli'' Agassiz." Palaeontology 1.2 (1958): 99-105. [http://cdn.palass.org/publications/palaeontology/volume_1/pdf/vol1_part2_pp99-105.pdf]</ref> Later, it was eventually determined that the last three species were portions of what would eventually be described as the [[heterostraci|heterostracan]] ''[[Pteraspis]] rostratus''. ''C. lyelli'', named after [[Sir Charles Lyell]],<ref name= white /> would be left to be the type species of the genus. Other researchers would continue adding other similar-looking osteostracans throughout the decades until, in 2009, Sansom reevaluated Osteostraci, and determined that only ''C. lyelli'' could be reliably placed within ''Cephalaspis'', and that probably all other species would eventually need to be reexamined and be placed into other genera.<ref name= sansom>Sansom, Robert S. "Phylogeny, classification and character polarity of the Osteostraci (Vertebrata)." Journal of Systematic Palaeontology 7.1 (2009): 95-115. [http://www.tandfonline.com/doi/abs/10.1017/S1477201908002551]</ref> In the same 2009 study, Sansom also determined that ''Cephalaspis'' ''[[sensu stricto]]'' was the sister-taxon of cornuate osteostracans, i.e., all osteostracans that either have, or have ancestors that had defined corners on the head-shields.<ref name= sansom />
+The genus ''Cephalaspis'' has long been used as a [[wastebasket taxon]] since [[Louis Agassiz|Agassiz]] erected it in 1835 for four species, ''C. lyelli'', ''C. rostratus'', ''C. lewisi'' and ''C. lloydi''.<ref name= white>White, E. I. "On ''Cephalaspis lyelli'' Agassiz." Palaeontology 1.2 (1958): 99-105. [http://cdn.palass.org/publications/palaeontology/volume_1/pdf/vol1_part2_pp99-105.pdf] {{Webarchive|url=https://web.archive.org/web/20151019234205/http://cdn.palass.org/publications/palaeontology/volume_1/pdf/vol1_part2_pp99-105.pdf |date=2015-10-19 }}</ref> Later, it was eventually determined that the last three species were portions of what would eventually be described as the [[heterostraci|heterostracan]] ''[[Pteraspis]] rostratus''. ''C. lyelli'', named after [[Sir Charles Lyell]],<ref name= white /> would be left to be the type species of the genus. Other researchers would continue adding other similar-looking osteostracans throughout the decades until, in 2009, Sansom reevaluated Osteostraci, and determined that only ''C. lyelli'' could be reliably placed within ''Cephalaspis'', and that probably all other species would eventually need to be reexamined and be placed into other genera.<ref name= sansom>Sansom, Robert S. "Phylogeny, classification and character polarity of the Osteostraci (Vertebrata)." Journal of Systematic Palaeontology 7.1 (2009): 95-115. [http://www.tandfonline.com/doi/abs/10.1017/S1477201908002551]</ref> In the same 2009 study, Sansom also determined that ''Cephalaspis'' ''[[sensu stricto]]'' was the sister-taxon of cornuate osteostracans, i.e., all osteostracans that either have, or have ancestors that had defined corners on the head-shields.<ref name= sansom />
 ===Included species===
 [[File:Cephalaspis Lyellii.jpg|thumb|right|''Cephalaspis lyellii'' reconstruction]]
 [[File:Cephalaspis lyelli.JPG|thumb|right|''Cephalaspis lyelli'' fossil]]
 [[File:Cephalaspis 2.jpg|thumb|right|''Cephalaspis lyelli'' fossil]]
-The following is a list of species that have been included into ''Cephalaspis''; most likely do not belong to the genus, but have not been formally moved.<ref name="groh">{{cite thesis | first1 = S. | last1 = Groh | title = Patterns of diversification in osteostracan evolution | chapter = Appendix | publisher = Uppsala University | type = M.S. | url = https://uu.diva-portal.org/smash/get/diva2:737117/FULLTEXT01.pdf}}</ref><ref>[http://users.atw.hu/fishindex/fosszilia%20taxa/cephalaspidomorphi.htm cephalaspidomorphi] at users.atw.hu/fishindex</ref>
+The following is a list of species that have been included into ''Cephalaspis''; most likely do not belong to the genus, but have not been formally moved.<ref name="groh">{{cite thesis | first1 = S. | last1 = Groh | title = Patterns of diversification in osteostracan evolution | chapter = Appendix | publisher = Uppsala University | type = M.S. | chapter-url = https://uu.diva-portal.org/smash/get/diva2:737117/FULLTEXT01.pdf}}</ref><ref>[http://users.atw.hu/fishindex/fosszilia%20taxa/cephalaspidomorphi.htm cephalaspidomorphi] at users.atw.hu/fishindex</ref>
-* †''Cephalaspis lyelli'' (Agassiz, 1835)
+* †''Cephalaspis lyelli'' (Agassiz, 1835) (type species)
 * †''"Cephalaspis" aarhusi'' (Wangsjö, 1952)
 * †''"Cephalaspis" agassizi'' (Lankester, 1868)
@@ Line 85: / Line 87: @@
 * †''Cephalaspis peninsula'' (Pageau, 1969)
 * †''Cephalaspis schrenckii'' (Pander, ?)
-* †''Cephalaspis sp.'' “Forfar” (Trewin & Davidson, 1996)
+* †''Cephalaspis sp.'' "Forfar" (Trewin & Davidson, 1996)
 * †''Cephalaspis syndenhami'' (Pageau, 1969)
 * †''Cephalaspis traquairi'' (Stensio, ?)
@@ Line 94: / Line 96: @@
 == References ==
-{{reflist}}
+{{Reflist}}
 *Janvier, P (1996) ''Early Vertebrates'' Oxford University Press;
 *Donoghue and Smith (2001) The anatomy of Turinia pagei (Powrie), and the phylogenetic status of the Thelodonti, Transactions of the Royal Society of Edinburgh: Earth Sciences, 92, p.&nbsp;15-37
@@ Line 100: / Line 102: @@
 == External links ==
 * Paleos Vertebrates [https://web.archive.org/web/20060313173034/http://www.palaeos.com/Vertebrates/Units/050Thelodonti/050.700.html#Cephalaspidida]
-* {{fossilworks|id=150011|title=''Cephalaspis''|date=03-01-2017}}
+* {{fossilworks|id=150011|title=''Cephalaspis''|date=3 January 2017}}
-{{portal|Paleontology}}
+{{Portal|Paleontology}}
+{{Osteostraci}}
+{{Taxonbar|from=Q133059}}
 [[Category:Fossil taxa described in 1835]]
 <!-- [[Category:Fossil taxa named by Louis Agassiz]] -->
-[[Category:Devonian fish of Europe]]
+[[Category:Early Devonian fish of Europe]]
 [[Category:Osteostraci genera]]
+[[Category:Paleozoic life of New Brunswick]]
+[[Category:Paleozoic life of Nova Scotia]]
+[[Category:Paleozoic life of Quebec]]