Eusthenopteron: Difference between revisions
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'''''Eusthenopteron''''' (from {{lang-el|εὖ}} {{transliteration|el|eû}}, 'good', {{lang-el|σθένος}} {{transliteration|el|sthénos}}, 'strength', and {{lang-el|πτερόν}} {{transliteration|el|pteron}} 'wing' or 'fin')<ref>{{cite book |last1=Miller |first1=S. A. (Samuel Almond) |title=North American geology and palæontology for the use of amateurs, students, and scientists |date=1889 |publisher=Cincinnati, O. : [Western Methodist book concern] |page=597 |url=https://archive.org/details/northamericangeo00milliala |access-date=6 January 2022}}</ref> is a [[genus]] of [[Prehistory|prehistoric]] [[Sarcopterygii|sarcopterygian]] (often called "lobe-finned") [[fish]]es |
'''''Eusthenopteron''''' (from {{lang-el|εὖ}} {{transliteration|el|eû}}, 'good', {{lang-el|σθένος}} {{transliteration|el|sthénos}}, 'strength', and {{lang-el|πτερόν}} {{transliteration|el|pteron}} 'wing' or 'fin')<ref>{{cite book |last1=Miller |first1=S. A. (Samuel Almond) |title=North American geology and palæontology for the use of amateurs, students, and scientists |date=1889 |publisher=Cincinnati, O. : [Western Methodist book concern] |page=597 |url=https://archive.org/details/northamericangeo00milliala |access-date=6 January 2022}}</ref> is a [[genus]] of [[Prehistory|prehistoric]] [[Sarcopterygii|sarcopterygian]] (often called "lobe-finned") [[fish]]es known from several [[species]] that lived during the Late [[Devonian]] [[Geological period|period]], about 385 million years ago. It has attained an iconic status from its close relationship to [[tetrapod]]s. Early depictions of animals of this genus show them emerging onto land, but [[Paleontology|paleontologists]] now widely agree that eusthenopteron species were strictly aquatic [[animal]]s.<ref name=LEA2007>M. Laurin, F. J. Meunier, D. Germain, and M. Lemoine 2007. [http://jpaleontol.geoscienceworld.org/content/81/1/143.abstract A microanatomical and histological study of the paired fin skeleton of the Devonian sarcopterygian ''Eusthenopteron foordi'']. ''Journal of Paleontology'' 81: 143–153.</ref> |
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The genus was first described by [[Joseph Frederick Whiteaves|J. F. Whiteaves]] in 1881, as part of a large collection of fishes from [[Nouvelle, Quebec|Miguasha]], [[Quebec]], [[Canada]].<ref>{{cite journal|last=Whiteaves|first=Joseph Frederick|title=On some remarkable fossil fishes from the Devonian rocks of Scaumenac Bay, in the Province of Quebec|journal=Annals and Magazine of Natural History|year=1881|volume=8|issue=44|pages=159–162|url=https://www.biodiversitylibrary.org/partpdf/68599|doi=10.1080/00222938109487434}}</ref> Some 2,000 ''Eusthenopteron'' specimens have been collected from Miguasha, one of which was the object of intensely detailed study and several papers by [[Evolution of fish|paleoichthyologist]] [[Erik Jarvik]] between the 1940s and the 1990s.<ref name=GSC_Jarvik> |
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Revision as of 18:24, 22 March 2024
![]() | This article may be too technical for most readers to understand.(February 2018) |
Eusthenopteron Temporal range: Late Devonian,
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Life restoration of Eusthenopteron foordi | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Sarcopterygii |
Clade: | Tetrapodomorpha |
Clade: | Eotetrapodiformes |
Family: | †Tristichopteridae |
Genus: | †Eusthenopteron Whiteaves, 1881 |
Species[1] | |
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Eusthenopteron (from Greek: εὖ eû, 'good', Greek: σθένος sthénos, 'strength', and Greek: πτερόν pteron 'wing' or 'fin')[2] is a genus of prehistoric sarcopterygian (often called "lobe-finned") fishes known from several species that lived during the Late Devonian period, about 385 million years ago. It has attained an iconic status from its close relationship to tetrapods. Early depictions of animals of this genus show them emerging onto land, but paleontologists now widely agree that eusthenopteron species were strictly aquatic animals.[3]
The genus was first described by J. F. Whiteaves in 1881, as part of a large collection of fishes from Miguasha, Quebec, Canada.[4] Some 2,000 Eusthenopteron specimens have been collected from Miguasha, one of which was the object of intensely detailed study and several papers by paleoichthyologist Erik Jarvik between the 1940s and the 1990s.[5]
Description
Eusthenopteron is a medium- to large-sized tristichopterid. E. foordi is estimated to exceed 1.5 m (4 ft 11 in), while E. jenkinsi probably reached 2.1 m (6 ft 11 in).[6][1]
The earliest known fossilized evidence of bone marrow has been found in Eusthenopteron, which may be the origin of bone marrow in tetrapods.[7]
Eusthenopteron shares many unique features in common with the earliest-known tetrapods. It shares a similar pattern of skull roofing bones with forms such as Ichthyostega and Acanthostega. Eusthenopteron, like other tetrapodomorph fishes, had internal nostrils (or a choana), one of the defining traits of tetrapodomorphs (including tetrapods). It also had labyrinthodont teeth, characterized by infolded enamel, which characterizes all of the earliest known tetrapods as well.
Unlike the early tetrapods, they did not have larval gills.[8]
Classification
![](http://upload.wikimedia.org/wikipedia/commons/thumb/a/af/Fishapods.svg/400px-Fishapods.svg.png)
Like other fish-like sarcopterygians, Eusthenopteron possessed a two-part cranium, which hinged at mid-length along an intracranial joint. Eusthenopteron's notoriety comes from the pattern of its fin endoskeleton, which bears a distinct humerus, ulna, and radius (in the fore-fin) and femur, tibia, and fibula (in the pelvic fin). These appendicular long bones had epiphyseal growth plates that allowed substantial longitudinal growth through endochondral ossification, as in tetrapod long bones.[9] These six appendicular bones also occur in tetrapods and are a synapomorphy of a large clade of sarcopterygians, possibly Tetrapodomorpha (the humerus and femur are present in all sarcopterygians). Similarly, its elasmoid scales lack superficial odontodes composed of dentine and enamel; this loss appears to be a synapomorphy with more crownward tetrapodomorphs.[10]
Eusthenopteron differs significantly from some later Carboniferous tetrapods in the apparent absence of a recognized larval stage and a definitive metamorphosis.[6] In even the smallest known specimen of Eusthenopteron foordi (at 29 mm), the lepidotrichia cover all of the fins, which does not happen until after metamorphosis in genera like Polyodon. This might indicate that Eusthenopteron developed directly, with the hatchling already attaining the adult's general body form (Cote et al., 2002).
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/1e/Eusthenopteron_model_at_AMNH.jpg/220px-Eusthenopteron_model_at_AMNH.jpg)
See also
References
- ^ a b Downs, Jason P.; Daeschler, Edward B.; Long, Alison M.; Shubin, Neil H. (2018). "Eusthenopteron jenkinsi sp. nov. (Sarcopterygii, Tristichopteridae) from the Upper Devonian of Nunavut, Canada, and a Review of Eusthenopteron Taxonomy". Breviora. 562 (1): 1–24. doi:10.3099/mcz44.1. ISSN 0006-9698. S2CID 51883892.
- ^ Miller, S. A. (Samuel Almond) (1889). North American geology and palæontology for the use of amateurs, students, and scientists. Cincinnati, O. : [Western Methodist book concern]. p. 597. Retrieved 6 January 2022.
- ^ M. Laurin, F. J. Meunier, D. Germain, and M. Lemoine 2007. A microanatomical and histological study of the paired fin skeleton of the Devonian sarcopterygian Eusthenopteron foordi. Journal of Paleontology 81: 143–153.
- ^ Whiteaves, Joseph Frederick (1881). "On some remarkable fossil fishes from the Devonian rocks of Scaumenac Bay, in the Province of Quebec". Annals and Magazine of Natural History. 8 (44): 159–162. doi:10.1080/00222938109487434.
- ^ Geological Survey of Canada (7 February 2008). "Past lives: Chronicles of Canadian Paleontology: Eusthenopteron - the Prince of Miguasha". Archived from the original on 11 December 2004. Retrieved 10 February 2009.
- ^ a b Schultze, H.-P. 1984. Juvenile specimens of Eusthenopteron foordi Whiteaves, 1881 (Osteolepiform rhipidistian, Pisces) from the Late Devonian of Miguasha, Quebec, Canada. Journal of Vertebrate Paleontology 4: 1-16.
- ^ Sanchez S, Tafforeau P and Ahlberg P E (2014) "The humerus of Eusthenopteron: a puzzling organization presaging the establishment of tetrapod limb bone marrow" Proceedings of the Royal Society B: Biological Sciences, 281 (1782): 20140299. doi:10.1098/rspb.2014.0299
- ^ Amphibian evolution : the life of early land vertebrates (page 141)
- ^ M. Laurin, F. and J. Meunier 2012. A microanatomical and histological study of the fin long bones of the Devonian sarcopterygian Eusthenopteron foordi. Acta Zoologica 93: 88–97.
- ^ Zylberberg, L., Meunier, F. J. and Laurin, M. 2010. A microanatomical and histological study of the postcranial dermal skeleton in the Devonian sarcopterygian Eusthenopteron foordi. Acta Palaeontologica Polonica 55: 459–470.
External links
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)