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Panderichthys BW
''Panderichthys'' is a genus of extinct sarcopterygian (lobe-finned fish) from the late Devonian period, about 380 Mya. ''Panderichthys'', which was recovered from Frasnian (early Late Devonian) deposits in Latvia, is represented by two species. ''P. stolbovi'' is known only from some snout fragments and an incomplete lower jaw. ''P. rhombolepis'' is known from several more complete specimens. Although it probably belongs to a sister group of the earliest tetrapods, ''Panderichthys'' exhibits a range of features transitional between tristichopterid lobe-fin fishes (e.g., ''Eusthenopteron'') and early tetrapods. It is named after the German-Baltic paleontologist Christian Heinrich Pander. Possible tetrapod tracks dating back to before the appearance of ''Panderichthys'' in the fossil record were reported in 2010, which suggests that ''Panderichthys'' is not a direct ancestor of tetrapods, but nonetheless shows the traits that evolved during the fish-tetrapod evolution Discover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radius (bone)
The radius or radial bone is one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna. The ulna is usually slightly longer than the radius, but the radius is thicker. Therefore the radius is considered to be the larger of the two. It is a long bone, prism-shaped and slightly curved longitudinally. The radius is part of two joints: the elbow and the wrist. At the elbow, it joins with the capitulum of the humerus, and in a separate region, with the ulna at the radial notch. At the wrist, the radius forms a joint with the ulna bone. The corresponding bone in the lower leg is the fibula. Structure The long narrow medullary cavity is enclosed in a strong wall of compact bone. It is thickest along the interosseous border and thinnest at the extremities, same over the cup-shaped articular surface (fovea) of the head. The trabeculae of the spongy t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Livoniana
''Livoniana'' is a genus of prehistoric Sarcopterygii, lobe-finned fish which lived during the Devonian geological period, period (Givetian - Frasnian faunal stages, stages, about 374 - 391 million years ago). This species is a transitional form between fish and the earliest tetrapods, like ''Tiktaalik'', ''Ichthyostega'' and ''Acanthostega''. Before ''Livoniana'' there was ''Elginerpeton'' and ''Obruchevichthys''. Four legs developed in water, not on land, to better escape waterliving predatory creatures like ''Hyneria''. There were very lush forests, and particularly swamps, where four limbs became very useful to avoid predators. References External links ''Livoniana multidentata'' at Devonian Times Elpistostegalians Prehistoric lobe-finned fish genera Transitional fossils Devonian fish of Europe {{paleo-lobefinned-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dipterus
''Dipterus'' (from el, δίς , 'two' and el, πτερόν 'wing') is an extinct genus of lungfish from the middle Devonian period of Europe and North America. In most respects, ''Dipterus'', which was about long, closely resembled modern lungfish. Like its ancestor ''Dipnorhynchus ''Dipnorhynchus'' is an extinct genus of lungfish from the middle Devonian period of Australia and Europe. ''Dipnorhynchus'' was a primitive lungfish, but still it had features that set it apart from other sarcopterygians. Its skull lacked the j ...'', it had tooth-like plates on its palate instead of real teeth. However, unlike its modern relatives, in which the dorsal fin, dorsal, caudal fin, caudal, and anal fin are fused into one, ''Dipteruss fins were still separated. The genus was established by Adam Sedgwick & Roderick Murchison in the year 1828. References Prehistoric lungfish genera Devonian bony fish Permian fish Carboniferous fish Triassic fish Devonian fish of Europe Fos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laccognathus
''Laccognathus'' is an extinct genus of amphibious fish, amphibious Sarcopterygii, lobe-finned fish from Europe and North America. They existed from the Middle Devonian to the Late Devonian (around 397.5 to 360 million years ago, mya). The name comes from Greek for 'pitted jaw'. Description Species of ''Laccognathus'' were characterized by the presence of three large pits (fossae) on the external surface of the lower jaw which may have had sensory functions. It is the origin of the genus name, from Ancient Greek language, Greek wikt:λάκκος, λάκκος ('pit') and wikt:γνάθος, γνάθος ('jaw'). ''Laccognathus'' grew to approximately in length. They had very short dorsoventrally flattened heads, less than one-fifth the length of the body. Like other sarcopterygians, their fins arise from pairs of fleshy lobes. The skeleton of ''Laccognathus'' was structured such that large areas of the skin were stretched out over solid plates of bone. This bone was composed of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plourdosteus
''Plourdosteus'' is an extinct genus of placoderm arthrodire which was relatively widespread in Euramerica during the Givetian to Frasnian ages of the Devonian. Etymology The name ''Plourdosteus'' commemorates the Plourde family at Miguasha National Park. Taxonomy ''Plourdosteus'' was previously assigned to the family Plourdosteidae within the Coccosteomorphi. However, subsequent studies found the family Plourdosteidae to be polyphyletic and should be dismissed. ''Plourdosteus'' was then proposed to be a member of Panxiosteidae. In the 2010 Carr & Hlavin phylogenetic study, Panxiosteidae was recognized as the sister taxon to the family Dunkleosteidae, which together comprised the superfamily Dunkleosteoidea (one of the three major clades of Eubrachythoraci). The phylogeny of ''Plourdosteus'' within Panxiosteidae is shown in the cladogram below from the 2013 Zhu & Zhu study: However, the subsequent 2016 Zhu ''et al.'' study using a larger morphological dataset recovered P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asterolepis (fish)
''Asterolepis'' is an extinct genus of antiarch placoderms from the Devonian of North and South America and Europe. They were heavily armored flat-headed benthic detritivores with distinctive jointed limb-like pectoral fins and hollow spine. The armor plate gives the ''Asterolepis'' a box-like shape. Its pectoral fins are also armored but the caudal and dorsal fin are not. The first fossils were named by M. Eichwald in 1840 after noticing star-like markings on the fossils. Etymology "Aster-" means star while "-lepis" means scales. Confusion surrounded the first fossils discovered of this genus, as naturalists were unable to ascertain their place among fishes and they were first named Chelonichthys. Later very fine specimens were found in the Old Red Sandstone of Russia and Professor Asmus of Dorpat sent them to the British Museum, noticing fossils exhibited star-like markings. That is when the name Chelonichthys was abandoned for ''Asterolepis'' which Eichwald proposed. Des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishapod Evolution
Elpistostegalia or Panderichthyida is an order of prehistoric lobe-finned fishes which lived during the Middle Devonian to Late Devonian period (about 385 to 374 million years ago). They represent the advanced tetrapodomorph stock, the fishes more closely related to tetrapods than the osteolepiform fishes. The earliest elpistostegalians, combining fishlike and tetrapod-like characters, are sometimes called fishapods, a phrase coined for the advanced elpistostegalian ''Tiktaalik''. Through a strict cladistic view, the order includes the terrestrial tetrapods. Palaeobiology of the elpistostegalians A rise in global oxygen content allowed for the evolution of large, predatory fish that were able to exploit the shallow tidal areas and swamplands as top predators. Several groups evolved to fill these niches, the most successful were the elpistiostegalians. In such environments, they would have been challenged by periodic oxygen deficiency. In comparable modern aquatic environments li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
