Temporal range: Late Devonian (Famennian), 365–360 Ma
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O
S
D
C
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J
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Reconstructed skeleton in Moscow Paleontological Museum
Skeletal reconstruction
Scientific classification
Domain:
Eukaryota
Kingdom:
Animalia
Phylum:
Chordata
Clade:
Sarcopterygii
Clade:
Tetrapodomorpha
Clade:
Stegocephali
Family:
†Ichthyostegidae Säve-Söderbergh, 1932
Genus:
†Ichthyostega Säve-Söderbergh, 1932
Type species
†Ichthyostega stensioei
Säve-Söderbergh, 1932
Other species[1][2]
†I. eigili Säve-Söderbergh, 1932
†I. kochi? Säve-Söderbergh, 1932
†I. watsoni Säve-Söderbergh, 1932
Synonyms
Genus synonymy
Ichthyostegopsis Säve-Söderbergh, 1932
Species synonymy
Ichthyostega stensiöi Säve-Söderbergh, 1932
Ichthyostegopsis wimani Säve-Söderbergh, 1932
Ichthyostega (from Greek: ἰχθῦςikhthûs, 'fish' and Greek: στέγηstégē, 'roof') is an extinct genus of limbed tetrapodomorphs from the Late Devonian of what is now Greenland. It was among the earliest four-limbed vertebrates ever in the fossil record and was one of the first with weight-bearing adaptations for terrestrial locomotion. Ichthyostega possessed lungs and limbs that helped it navigate through shallow water in swamps. Although Ichthyostega is often labelled a 'tetrapod' because of its limbs and fingers, it evolved long before true crown group tetrapods and could more accurately be referred to as a stegocephalian or stem tetrapod. Likewise, while undoubtedly of amphibian build and habit, it is not a true member of the group in the narrow sense, as the first modern amphibians (members of the group Lissamphibia) appeared in the Triassic Period. Until finds of other early stegocephalians and closely related fishes in the late 20th century, Ichthyostega stood alone as a transitional fossil between fish and tetrapods, combining fish and tetrapod features. Newer research has shown that it had an unusual anatomy, functioning more akin to a seal than a salamander, as previously assumed.[3]
^Haaramo, Mikko. "Taxonomic history of the genus †Ichthyostega Säve-Söderbergh, 1932". Mikko's Phylogeny Archive. Blom, 2005. Retrieved 24 October 2015.
^"Ichthyostega". Paleofile. Retrieved 24 October 2015.
^Cite error: The named reference pierce2012 was invoked but never defined (see the help page).
Ichthyostega (from Greek: ἰχθῦς ikhthûs, 'fish' and Greek: στέγη stégē, 'roof') is an extinct genus of limbed tetrapodomorphs from the Late Devonian of...
more basal than Ichthyostega, it is possible that Acanthostega was actually more derived. Since Acanthostega resembles juvenile Ichthyostega and shows a lot...
and digits evolved in the Devonian, including the Late Devonian-age Ichthyostega and Acanthostega, as well as the trackmakers of the Middle Devonian-age...
first described, the order's sole member was Ichthyostega, from which the group takes its name. Ichthyostega was seen as transitional between fish and the...
primitive than other Devonian tetrapodomorphs including Acanthostega and Ichthyostega, and helps further understanding of the fish-tetrapod transition. Walter...
portion of the stem group, the earliest limbed tetrapodomorphs such as Ichthyostega and Acanthostega, which evolved in the Devonian period long before the...
stem tetrapods from Greenland, Acanthostega and Ichthyostega, Ymeria is most closely related to Ichthyostega, though the single known specimen is smaller...
at the back edge of the skull. In earlier fully aquatic forms such as Ichthyostega, it may have formed an open spiracle. In later terrestrial forms such...
(overlapping) via blade-like flanges. Imbricating ribs are also known in Ichthyostega, though in that taxon the ribs are more diverse in shape. Tiktaalik most...
examples of species showing transitional features have been discovered. Ichthyostega was one of the first primitive amphibians, with nostrils and more efficient...
named Andreyevka. This genus and the closely related Acanthostega and Ichthyostega represent the earliest tetrapods. Tulerpeton is considered one of the...
with some of the early tetrapods such as the Devonian Acanthostega and Ichthyostega, and unique triassic animals such as the phytosaur Mystriosuchus alleroq...
raising them out of water. A 2012 study using 3D reconstructions of Ichthyostega concluded that it was incapable of typical quadrupedal gaits. The limbs...
among them Acanthostega, which seems to have been wholly aquatic, and Ichthyostega" Richard Dawkins 2004 The Ancestor's Tale p. 250, ISBN 0-618-00583-8...
intermediate between the earliest Devonian terrestrial vertebrates (such as Ichthyostega), and the different groups ancestral to all modern tetrapods, such as...
Early groups like Acanthostega had eight digits, while the more derived Ichthyostega had seven digits, the yet-more derived Tulerpeton had six toes. Tetrapods...
weed-filled swamps, such as Acanthostega which had feet with eight digits and Ichthyostega with limbs. Descendants also included pelagic lobe-finned fish such as...
weight-bearing abilities compared to other Devonian limbed vertebrates such as Ichthyostega and Acanthostega. The cleithrum (upper blade of the shoulder) is fused...
similar pattern of skull roofing bones with stem tetrapoda forms such as Ichthyostega and Acanthostega. Eusthenopteron, like other tetrapodomorph fishes, had...
as such include: Tiktaalik (transition between fish and amphibians) Ichthyostega (transition between amphibians and reptiles) Mammal-like reptiles (not...
Acanthostega and Ichthyostega reveal that they had different habits. Acanthostega is likely exclusive to an aquatic environment, while Ichthyostega is progressed...
(April 28, 2008). "Bipedal orangs, gait of a dinosaur, and new-look Ichthyostega: exciting times in functional anatomy part I". Tetrapod Zoology. Archived...
380 million years old, and early tetrapods such as Acanthostega and Ichthyostega, known from fossils about 365 million years old. Its mixture of primitive...
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