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Chordates
Encyclopedia entry from: The Gale Encyclopedia of Science
...Other defining features of chordates are the presence of pharyngeal...the more recently evolved chordates, such as the vertebrates. Chordate animals have a closed circulatory...systemic circulation). Most chordates have two sexes, and the...
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chordates
Book article from: The Oxford Companion to the Earth
...show the full complement of chordate characters. The cephalochordates...about 7 cm long) in which the chordate characters are retained in...Although they retain the chordate characters as adults gill...of cell division shows that chordates are most closely related to...
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chordate
Book article from: World Encyclopedia
chordate Any member of the Chordata, a large phylum of vertebrates and some marine...like, cartilaginous supporting structures ( notochords ). Invertebrate chordates are divided into three subphyla: tunicates (seasquirts); Cephalochordata...
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Chordata
Book article from: The Columbia Encyclopedia, Sixth Edition
...three features unique to chordates and found in all of them...shows affinities with chordates and has sometimes been considered a chordate subphylum, but is now often...show affinities to other chordates only in the juvenile stage...
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Arrow worms
Encyclopedia entry from: The Gale Encyclopedia of Science
...vertebrates), but they lack many important chordate characteristics. Nevertheless, arrow...cavity), which is a characteristic of chordates and the phylum Protochordata. In arrow...the phylum Chordata. However, most chordates have a coelom that arises in a different...
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vertebrates
Book article from: The Oxford Companion to the Earth
...the phylum Chordata and retain the chordate characters of a notochord (a longitudinal...successful and widespread than their chordate relatives the urochordates and cephalochordates. These lower chordates are marine filter-feeders, and it...
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lancelet
Book article from: The Columbia Encyclopedia, Sixth Edition
lancelet name for small, fishlike lower chordate (see Chordata ), also called amphioxus; it shows many affinities...feeding rather than respiration is characteristic of the lower chordates (see tunicate ). The lancelet has a dorsal notochord, or...
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Hemichordata
Book article from: The Columbia Encyclopedia, Sixth Edition
...related to both the echinoderms (phylum Echinodermata ) and chordates (phylum Chordata ). Acorn worms, class Enteropneusta...a hollow nerve cord in the collar suggest relationship to chordates, while the ciliated larvae are similar to those of echinoderms...
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Burgess shale
Book article from: World Encyclopedia
...Cambrian period. The silt has preserved traces of many of the soft bodies of sea creatures. The fossils include the oldest known chordate – a forerunner of all animals with backbones. They also include a number of kinds of animals that have completely...
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notochord
Book article from: World Encyclopedia
notochord In chordates , such as acorn worms, and the early embryonic stages of vertebrates, the flexible, primitive backbone; in mature vertebrates it is replaced by the spine .
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