Notacanthiformes
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Notacanthiformes
[‚nōd·ə‚kan·thə′fȯr·mēz] (vertebrate zoology)
An order of actinopterygian fishes whose body is elongated, tapers posteriorly, and has no caudal fin.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.