▪ fossil amphibian genus
 genus of extinct animals, closely related to tetrapods (four-legged land vertebrates) and found as fossils in rocks in eastern Greenland from the late Devonian Period (about 370 million years ago). Ichthyostega was about one metre (three feet) long and had a small dorsal fin along the margin of its tail; the tail itself possessed a series of bony supports, typical of the tail supports that are found in fishes. Other traits retained from earlier aquatic vertebrates include the relatively short snout region, the presence of a preopercular bone in the cheek region (which serves as part of the gill cover in fishes), and many small scales on the body. Advanced traits shared with tetrapods include a series of robust bones supporting the fleshy limbs, a lack of gills, and strong ribs. Ichthyostega and its relatives represent forms slightly more advanced than the aquatic Eusthenopteron and appear to be near the evolutionary line leading to the first tetrapods on land. It is possible that the ichthyostegids persisted into the following Carboniferous Period.

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Universalium. 2010.

Look at other dictionaries:

  • Ichthyostega — Rekonstruktion des Schädels von Ichthyostega im Geologischen Museum von Kopenhagen Zeitraum Oberdevon 370 bis 360 Mio. Jahre Fundorte …   Deutsch Wikipedia

  • Ichthyostéga — Ichthyostega Ichthyostéga …   Wikipédia en Français

  • Ichthyostega —   [griechisch], Gattung fossiler Amphibien, mit plumpem Körper und Flossensaum am Schwanzende; Hauptvertreter der Ichthyostegalia (Fischschädellurche), einer ausgestorbenen Ordnung bis 1 m langer, primitiver Schwanzlurche (zur Unterklasse… …   Universal-Lexikon

  • Ichthyostega —   Ichthyostega Escala temporal: Devónico …   Wikipedia Español

  • Ichthyostega — Taxobox name = Ichthyostega fossil range = Fossil range|367|362.5 Famennian (Late Devonian) image width = 250px image caption = Life restoration of Ichthyostega after Ahlberg, 2005. regnum = Animalia phylum = Chordata superclassis = Tetrapoda… …   Wikipedia

  • Ichthyostega — I. stensioei I. watsoni I. eigili I. kochi Ichthyostega Säve Söderbergh, 1932 es un extinto miembro del género tetrápodo que vivió durante el período Devónico superior (Fameniano), aproximadamente hace 367 362,5 millones de años, y el primero en… …   Enciclopedia Universal

  • Ichthyostega — Ichtyostéga …   Wikipédia en Français

  • Ichthyostega — …   Википедия

  • Ichthyostega — Ich|thy|os|te|ga* der; Gen. od. s, Plur. ...g’alia <zu ↑ichthyo... u. gr. stégos »Dach« (wegen des beschuppten Körpers)> ausgestorbener, erdgeschichtlich ältester Lurch des Oberdevons …   Das große Fremdwörterbuch

  • genus Ichthyostega — noun second earliest fossil amphibian ever found; of the Devonian; found in Greenland • Hypernyms: ↑amphibian genus • Member Holonyms: ↑amphibia, ↑class Amphibia • Member Meronyms: ↑Ichyostega …   Useful english dictionary

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