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Ichthyostega

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Series: Geological Society, London, Special Publications
Published: 01 January 2010
DOI: 10.1144/SP339.9
EISBN: 9781862395879
... both Ichthyostega and Acanthostega ) is reinterpreted. The Britta Dal Formation channels have flat bases, are poorly channelized, are of low sinuosity and are part of a very major distributory system that periodically experienced extreme flooding. The tetrapod fossils were recovered from...
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Journal Article
Journal: Geology
Published: 01 July 1999
Geology (1999) 27 (7): 637–640.
... succession that has yielded Acanthostega and Ichthyostega , two tetrapods that are regarded as critically important taxa for our understanding of the origin and early evolution of the tetrapods. These palynological assemblages conclusively show that the rocks are Devonian in age. The evidence resolves a 60...
Journal Article
Journal: Geology
Published: 01 August 1997
Geology (1997) 25 (8): 675–678.
... and paleomagnetic data. A Carboniferous age for the strata has significant implications for vertebrate evolution; fossils of a terrestial tetrapod, Ichthyostega , are found above the unconformity. Ichthyostega is regarded as the earliest fossil of an animal known to walk on land; however, our data suggest...
Series: GSA Memoirs
Published: 01 January 2008
DOI: 10.1130/2008.1202(11)
... of the earliest four-legged vertebrates, the tetrapods later assigned to the genus Ichthyostega . Basin initiation in East Greenland was caused mainly by extensional collapse of an overthickened Caledonian crustal welt accommodated by SE-NW–oriented dip-slip faulting and, subordinately, by N-S–oriented sinistral...
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Journal Article
Published: 01 March 2000
Journal of Paleontology (2000) 74 (2): 301–308.
... and a longitudinal dorsal ridge on the prearticular. The size of this lower jaw fragment also meets the expected dimensions for Hynerpeton based on the size of the shoulder girdle and using Ichthyostega as a model for proportions. F igure 1 —ANSP #20901, posterior portion of right lower jaw...
FIGURES
Journal Article
Published: 01 November 2010
Journal of Paleontology (2010) 84 (6): 1135–1151.
... order. The descriptions are supported by Figures 1–3 . The mandible was described and illustrated by Bolt and Lombard, 2001 . A midline unpaired postparietal is a derived state for tetrapods. Among Devonian and Mississippian tetrapods it occurs only in Ichthyostega ( Jarvik, 1996 ). The state...
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Journal Article
Published: 13 October 2020
Canadian Journal of Earth Sciences (2020) 57 (11): 1365–1369.
... and Smithson 1990 ). Ichthyostega , which does not have torsion of the fibula, is proposed to have moved more like a seal ( Pierce et al.2012 ) although this mode of locomotion is not inferred from its fibular morphology. As discussed above, the element is similar to the Carboniferous tetrapod Pederpes...
FIGURES
Journal Article
Published: 01 May 2000
Geological Magazine (2000) 137 (3): 342.
... written, readable, not too cluttered with technical terms and reasonably up-to-date. Some areas could be more ‘up to speed’ such as the discussion of the early tetrapods, which is the old-style ‘unimproved’ Ichthyostega story. There seems to have been a lag of a couple of years between the youngest...
Journal Article
Published: 01 November 2001
Journal of Paleontology (2001) 75 (6): 1202–1213.
... , in which all radials are preaxial; 3, hind limb of the early tetrapod Ichthyostega , in which the axis of development angles forward and the distal tarsals and digits develop in a posterior to anterior sequence; 4, area of expression of Hoxd 13 in the living zebra fish; 5, area of expression...
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Image
Figure  2 —Changes in the axis of development and the expression of  Hox  g...
Published: 01 November 2001
of the osteolepiform fish Eusthenopteron , in which all radials are preaxial; 3, hind limb of the early tetrapod Ichthyostega , in which the axis of development angles forward and the distal tarsals and digits develop in a posterior to anterior sequence; 4, area of expression of Hoxd 13 in the living zebra
Series: Geological Society, London, Special Publications
Published: 01 January 2000
DOI: 10.1144/GSL.SP.2000.180.01.29
EISBN: 9781862394285
... the Upper Devonian sequence of East Greenland were first discovered by Nathorst and reported by Woodward ( 1901 ), but the fauna has been held in special regard by palaeontologists since it was found to include the tetrapod genus Ichthyostega. For many years this was the earliest known tetrapod (Säve...
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Journal Article
Published: 03 July 2015
Geological Magazine (2016) 153 (1): 112–127.
... Holoptychius sp. Dipnoiformes Dipteridae indet. Jarvikia sp. Tetrapodomorpha Tetrapoda Ichthyostega-like ‘Osteolepiformes’ Litoptychius -like Acanthodii Acanthodii indet. Lithological unit UL7 – Bed D–D’ Plants Tracheophyta Gymnospermopsida Moresnetia...
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Journal Article
Published: 01 January 2007
Journal of Paleontology (2007) 81 (1): 143–153.
... of lepidotrichia in the caudal fin, reduction of the internal gills (gill arches generally cartilaginous and not grooved for afferent branchial artery, contrary to Acanthostega Jarvik, 1952 and Ichthyostega Säve-Söderbergh, 1932 ) The new microanatomical data on the endoskeletal fin bones...
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Journal Article
Published: 11 March 2010
Canadian Journal of Earth Sciences (2010) 47 (3): 209–219.
.... Although this may represent the neural or haemal spine of the terminal vertebra, both its horizontal orientation and greater length compared with adjacent spines suggest that it may represent a urostyle. This structure has been reported in the archaic tetrapods Ichthyostega ( Jarvik 1996 ) and Acanthostega...
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Journal Article
Published: 01 September 2000
Journal of Paleontology (2000) 74 (5): 938–956.
... taxon. Until recently ( Clack, 1994, 1998 ) the contemporaneous Ichthyostega would have assumed this role. However, whereas the braincase in Ichthyostega is poorly known and remains problematical, that in Acanthostega is presently the only one completely described for a Devonian tetrapod...
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Figure  1 —Sarcopterygian phylogeny showing the position of  Eusthenopteron...
Published: 01 January 2007
in the caudal fin, reduction of the internal gills (gill arches generally cartilaginous and not grooved for afferent branchial artery, contrary to Acanthostega Jarvik, 1952 and Ichthyostega Säve-Söderbergh, 1932 )
Journal Article
Journal: Paleobiology
Published: 01 January 2001
Paleobiology (2001) 27 (1): 1–6.
... is adopted. For vernacular terms, such restricted crown-group definitions are clearly inappropriate—for instance, applying crown-group interpretations would mean that Ichthyostega is not a tetrapod, Morganucodon is not a mammal, and Archaeopteryx is not a bird. All these extinct forms have evolved...
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Journal Article
Published: 01 May 2006
Journal of Paleontology (2006) 80 (3): 561–580.
... such as Ichthyostega stensoei Säve-Söderbergh, 1932 ( Jarvik, 1996 ) or Acanthostega gunnari ( Coates, 1996) , which have a different morphology. In these taxa the cleithral shaft is absent, the scapular blade is comparatively undeveloped, and the cleithrum and scapulocoracoid are co-ossified in all specimens...
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Journal Article
Published: 01 September 2001
Journal of Paleontology (2001) 75 (5): 1016–1042.
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Journal Article
Published: 01 June 1987
Journal of the Geological Society (1987) 144 (3): 495–506.
... Journal of Geology 1985 21 123 42 Smeldnaes N. Gallitelli E. M. Palaeoecology of Ichthyostega and the origin of the terrestrial vertebrates Palaeontology, Essential of Historical Geology 1982 1 Modena Mucchi 323 43 Thayer D. W. New Pennsylvanian lepospondyl...