Ostracoderms definition
WebDefinitions of ostracoderm noun extinct fish-like jawless vertebrate having a heavily armored body; of the Paleozoic see more Think you’ve got a good vocabulary? Take our … Webostracoderm. Definition in the dictionary English. ostracoderm. Definitions. noun (zoology) grammar. Any of the armored jawless fishes of the Paleozoic. noun. extinct fish …
Ostracoderms definition
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WebThe Osteostraci (bony armored jawless fish) are generally considered the sister taxon of Gnathostomata. [2] [8] [9] Jaw development in vertebrates is likely a product of the supporting gill arches. This development would help push water into the mouth by the movement of the jaw, so that it would pass over the gills for gas exchange. WebIn ostracoderms, we find a hint of vertebral column. Since then, the evolution of vertebral column in fishes and tetrapods is most complicated, because some parts of vertebral column are enlarged, others were lost, and some were evolved independently several times. ... Definition: The mechanism by which the upper jaw (palatoquadrate) and ...
Web3. External Features of Lamprey: The body comprises a cylindrical head and trunk and laterally flattened tail. The paired fins are absent, but the tail bears a median fin, which is expanded in front as a dorsal fin. In female the anal fin is present while in male copulatory papilla is found. Webostracoderm [ ŏs ′trə-kŏ-dûrm′ ] Any of various extinct primitive jawless fishes of the Ordovician through the Devonian Period. Most ostracoderms had their heads or entire …
WebStudy with Quizlet and memorize flashcards containing terms like 1. All chordates have a. a single, dorsal, tubular, nerve cord. b. a ventral heart. c. pharyngeal slits. d. a postanal tail as some stage. e. all of the choices are chordate features., 2. Although several invertebrate groups have been proposed as chordate ancestors, most zoologists now believe the … Web: a subphylum or other division of Chordata comprising the tunicates and including the classes Ascidiacea, Thaliacea, and Larvacea Word History Etymology New Latin, from ur- entry 2 + Chordata Love words?
WebThese were jawless, armored fish informally called ostracoderms, but more correctly placed in the taxon Pteraspidomorphi. Typical Ordovician fish had large bony shields on the head, small, rod-shaped or platelike scales covering the …
WebWhat does the word ostracoderm mean? Find and lookup the definition, synonyms, and antonyms of the word ostracoderm in our free online dictionary! healthdirect australia nswWebOstracoderms were small fishes, often less than 1 foot (30 cm) long and were probably slow, bottom-dwelling animals. Their fins were small, and they lacked lateral fins, but did have medial fins. They had permanently open mouths. Another innovation of ostracoderms was the use of gills not for feeding, but exclusively for respiration. In all ... gone with the wind ellenOstracoderms (lit. 'shell-skins') are the armored jawless fish of the Paleozoic Era. The term does not often appear in classifications today because it is paraphyletic (excluding jawed fishes) (may also be polyphyletic if anaspids are closer to cyclostomes) and thus does not correspond to one evolutionary lineage. However, the term is still used as an informal way of loosely grouping togethe… gone with the wind essayWebnoun Any of various extinct primitive jawless fishes of the Ordovician through the Devonian periods, having bodies encased in an armor of bony plates. American Heritage Similar … gone with the wind exhibit austin txWebOct 14, 2024 · Definition. Phylogenetics is a branch of biology that deals with studying and determining the evolutionary relationships, or patterns of descent, of groups of organisms. There are three types of ... gone with the wind fabulous memeWebJan 5, 2024 · Science Introduction Ostracoderms (shell-skinned) are of several groups of extinct, primitive, jawless fishes that were covered in an armour of bony plates. They … gone with the wind extracthealthdirect australia privacy policy