Copyright © Philip M. Parker, INSEAD. Terms of Use.

Definition: Tetrapod |
TetrapodNoun1. A vertebrate animal having four feet or legs or leglike appendages. Source: WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved. |
Etymology: Tetrapod \Tet"ra*pod\, noun. [Greek expression fourfooted; te`tra- (see Tetra-) + foot.]. (Websters 1913) |
| Context | Synonyms within Context (source: adapted from Roget's Thesaurus). |
Four | Tetrapod. |
| Source: adapted from Roget's Thesaurus. | |
(From Wikipedia, the free Encyclopedia)
A tetrapod is a vertebrate animal having four feet, legs or leglike appendages. The technical term tetrapoda literally means 'four-legged' (from the Greek).
The evolution of the air-breathing lung from the primitive swim-bladder of lobe-finned fishes has not yet been worked out in detail. Functioning internal gills were present in in at least one Late Devonian tetrapod, Acanthostega.
These earliest tetrapods were not terrestrial. The earliest confirmed terrestrial forms are known from the early Carboniferous deposits, some 20 million years later. At last they would have used their legs to paw their way through the mud.
During the 'gap' tetrapod backbones developed, limbs with digits and other adaptations for terrestrial life and walking gaits. But limbs were not the only organs involved. Ears, skulls and vertebral columns all underwent changes too. The number of digits on manes (hand) and (pes) foot became standardized. The very few tetrapod fossils in the 'gap' are all the more precious. Jennifer A. Clack, Gaining Ground: the origin and evolution of tetrapods analyzes them.
By the Visean era of mid-Carboniferous times, recognizable basal-group Amphibia (frogs, salamanders and caecilians) are represented by the temnospondyls and similarly primitive Amniota (which now include mammals, turtles, crocodiles, birds, lizards and snakes) are represented by the anthracosaurs. Living members of the tetrapod clan (that is, 'crown-group') tetrapods represent the phylogenetic end-points of these two divergent lineages. A third Palaeozoic group, the baphetids left no modern survivors.
Today, most tetrapods are land-dwelling, at least in their adult forms, but some species, such as the axolotl remain aquatic. whales and ichthyosaurs are tetrapods that have returned to the sea.
;Amphibia : frogs and toads, newts and salamanders
;Anapsida : only extant examples are turtles
;Synapsida : many extinct species and all mammals
;Dyapsida : dinosaurs, most modern reptiles, birds
Note that snakes are considered tetrapods because they are descended from ancestors who had a full complement of limbs. Similar considerations apply to aquatic mammals.Devonian tetrapods
The first tetrapods evolved in shallow and swampy freshwater habitats, towards the end of the Devonian period, a bit more than 360 million years ago. The primitive tetrapods developed from osteolopiform lobe-fin fishes, the Sarcopterygii— the 'living fossil' coelacanth is a lobe-finned fish— which had already developed some adaptations of fins with fleshy bases and bones, which they used as paddles in shallow water habitats choked with plants and detritus. The universal tetrapod characters of front limbs that bend backward at the elbow and hind limbs that bend forward at the knee can plausibly be traced to early tetrapods living in shallow water.Devonian tetrapods: external links
Carboniferous tetrapods
Until the 1990s, there was a 30- million year gap in the fossil record between the late Devonian tetrapods and the reappearance of tetrapod fossils, in recognizable amphibian lineages, in the mid-Carboniferous. It was referred to as 'Romer's Gap' for the palaeontologist who recognized it.Carboniferous tetrapods: external links
In the Permian period the term 'tetrapoda' becomes less useful, as the separate tetrapod lineages each developed in their own way. Each lineage, however, remained part of the tetrapoda, just as Homo sapiens could be considered a very highly-specialized kind of lobe-finned fish!
There are four main categories of living ('crown group") tetrapods:
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Tetrapod."
Crosswords: Tetrapod |
| English words defined with "tetrapod": Cynodontia ♦ division Cynodontia ♦ Ichyostega. (references) |
| Domain | Title |
Books | |
Source: compiled by the editor from various references; see credits. | |
| The following statistics estimate the number of searches per day across the major English-language search engines as identified by various trade publications. Hyperlinks lead to commercial use of the expression at Amazon.com. |
| Expression | Frequency per Day |
tetrapod | 5 |
| Source: compiled by the editor from various references; see credits. | |
| Language | Translations for "tetrapod"; alternative meanings/domain in parentheses. | ||||
Bulgarian | четириного животно, четириного (quad, quadruped). (various references) | ||||
Danish | tetrapode. (various references) | ||||
Dutch | pitbetonblok. (various references) | ||||
French | tétrapode. (various references) | ||||
German | Tetrapode, vierfüßler (quadruped, quadrupeds), vierfüßer (quadruped). (various references) | ||||
Italian | tetrapode. (various references) | ||||
Japanese Kanji | テキスト終結 (end of text, rough texture, technetium, technetronic, technical, technical center, technical foul, technical knockout, technical point, technical term, technician, Technicolor, technics, technique, techno cut, techno lady, techno mart, techno sound, technocracy, technocrat, technoeconomics, technologies, technology, technology art, technology assessment, technology gap, technology transfer, technomist, technonationalism, technopeasant, technophobia, technopolis, techno-pop, techno-science, techno-stress, technostructure, teddy, teddy bear, Tektronics, tenant, tennis, tennis court, tennis elbow, tennis-wear, tenor, tenor sax, test, test campaign, test case, test driver, test marketing, test pattern, test pilot, test rider, testament, tester, testing, test-mail, testosterone, test-set, Tetoron, tetrachloroethylene, tetracycline, Tetrapack, Tetris, tetrodotoxin, texture). (various references) | ||||
Japanese Katakana | テトラポッド . (various references) | ||||
Pig Latin | etrapodtay | ||||
Derivations | |
Words beginning with "tetrapod": tetrapods. (additional references) | |
| Source: compiled by the editor, based on several corpora (additional references). | |
| Words rhyming with "tetrapod" (pronounced 'Tet"ra*pod'): Adelopod, Arthropod, Baenopod, Brachiopod, Branchiopod, Cercopod, Chaetopod, Chilopod, Condylopod, Copepod, Decapod, Diplopod, gastropod, Gnathopod, Haemapod, Heteropod, Hexapod, isopod, Laemodipod, lycopod, Macropod, mastigopod, Myriapod, Myxopod, Neuropod, Octopod, Peraeopod, Phyllopod, Physopod, Platypod, Pleopod, Poecilopod, Pseudopod, Pteropod, Pygopod, rhizopod, Steganopod, Stomapod, stomatopod, Trachelipod, tripod, Uropod. (additional references) |
Scrabble® Enable2K-Verified Anagrams | |
| Words within the letters "a-d-e-o-p-r-t-t" | |
-1 letter: adopter, readopt, rotated. | |
-2 letters: depart, deport, dotter, orated, parted, patted, patter, petard, ported, potted, potter, prated, protea, ratted, redtop, rotate, rotted, tarted, teapot, tetrad. | |
-3 letters: adept, adopt, adore, aport, apter, dater, datto, depot, derat, doper, doter, drape, dropt, oared, oater, opera, opted, orate, oread, ottar, otter, padre, pared, pareo, pated, pater, peart, pedro, petto, pored, prate, raped, rated, repot, roped, rotte, taped, taper, tardo, tared, tarot, tater, tetra, toped, toper, torte, toted, toter, trade, trapt, tread, treat, trode, trope. | |
-4 letters: aero, aped, aper, apod, atop, dare, dart, date, dato, dear, doat, doer, dopa, dope, dore, dorp, dote, drat, drop, odea, oped, orad, pard, pare, part, pate, pear, peat, pert, poet, pore, port, prao, prat, proa, prod, rape, rapt, rate, rato, read, reap, redo, repo, road, rode, rope, rota, rote, tape, tare, taro, tarp, tart, tate, tear, teat, tepa, toad, toea, toed, tope, tora, tore, tort, tote, trad, trap, tret, trod, trop, trot. | |
-5 letters: ado, ape, apt, are, art, ate, att, dap, doe, dor, dot, ear, eat, era, eta, oar, oat, ode, ope, opt, ora, ore, ort, pad, par, pat, pea, ped, per, pet, pod, pot, pro, rad, rap, rat, red, rep, ret, rod, roe, rot, tad, tae, tao, tap, tar, tat, tea, ted, tet, tod, toe, top, tor, tot. | |
| Words containing the letters "a-d-e-o-p-r-t-t" | |
+1 letter: tetrapods. | |
+2 letters: prostrated, protonated, protracted, tetraploid. | |
+3 letters: decapitator, deportation, partitioned, preallotted, propitiated, pterodactyl, spatterdock, tetraploids, tetraploidy, transported, trepidation. | |
+4 letters: antipredator, bootstrapped, carrottopped, decapitators, deportations, dermatophyte, expectorated, extrapolated, interpolated, postgraduate, preformatted, premeditator, privatdocent, privatdozent, pterodactyls, spatterdocks, trepidations. | |
+5 letters: antipredators, compartmented, cotransported, decrepitation, dermatophytes, electroplated, postdoctorate, postgraduates, preadaptation, predestinator, premeditation, premeditators, privatdocents, privatdozents, repartitioned, tetraploidies. | |
| Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. | |
Hexadecimal (or equivalents, 770AD-1900s) (references)54 65 74 72 61 70 6F 64 |
| Leonardo da Vinci (1452-1519; backwards) (references)
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| American Sign Language (origins from 1620-1817 in Italy and, especially, France) (references)
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| Semaphore (1791, in France) (references)
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| Braille (1829, in France) (references)
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Morse Code (1836) (references)- . - .-. .- .--. --- -.. |
| Dancing Men (Sir Arthur Conan Doyle, 1903) (references)
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Binary Code (1918-1938, probably earlier) (references)01010100 01100101 01110100 01110010 01100001 01110000 01101111 01100100 |
HTML Code (1990) (references)T e t r a p o d |
ISO 10646 (1991-1993) (references)0054 0065 0074 0072 0061 0070 006F 0064 |
| British Sign Language (Fingerspelling, BSL; 1992, British Deaf Association Dictionary of British Sign Language) (references)
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Encryption (beginner's substitution cypher): (references)5471868467828170 |
| 1. Definition 2. Crosswords 3. Usage: Commercial 4. Expressions: Internet | 5. Translations: Modern 6. Derivations 7. Rhymes 8. Anagrams | 9. Orthography 10. Bibliography |
Copyright © Philip M. Parker, INSEAD. Terms of Use.