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Related to Urostyle: keel bone


(vertebrate zoology)
An unsegmented bone representing several fused vertebrae and forming the posterior part of the vertebral column in Anura.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a rodlike bone in the caudal portion of the vertebral column of some vertebrates, formed by the fusion of all caudal vertebrae (in salientians) or of only the terminal caudal vertebrae (in bony fishes). Together with the hypural bones, the urostyle supports the radials of the homocercal fin of bony fishes.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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ULABG 463 with anterior part of dorsum greenish-brown, and irregular dark spots on top of head, at level of shoulders and sacral and urostyle regions; inguinal band broken in dots towards anterior part (on right flank); belly whitish, throat uncolored, darker than belly; pale tympanum.
Counts were made from a radiograph of the holotype and from each specimen where possible; vertebral counts include the urostyle. The first caudal vertebra is that with the haemal spine supporting the first anal-fin ray.
Myomeres were difficult to count reliably at either end and thus vertebral counts (which include the urostyle) of stained larvae were taken instead.
Measurements were taken from the tip of the snout to the end of the notochord in preflexion larvae (notochord length), and from the tip of the snout to the end of the urostyle or hypural plate (whichever was more distal) in flexion or postflexion larvae (standard length).