Internasal scales

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Nomenclature of scales (top view of head) AB045 Scales on a snakes head.jpg
Nomenclature of scales (top view of head)

In snakes, the internasal scales are those on top of the head between the scales that surround the nostrils. [1] They are usually paired and situated just behind the rostral. [2]

Rostral scale

The rostral scale, or rostral, in snakes and other scaled reptiles is the median plate on the tip of the snout that borders the mouth opening. It corresponds to the mental scale in the lower jaw. The term pertains to the rostrum, or nose. In snakes, the shape and size of this scale is one of many characteristics used to differentiate species from one another.

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The mental scale, or mental, in snakes and other scaled reptiles refers to the median plate on the tip of the lower jaw. It is a triangular scale that corresponds to the rostral of the upper jaw. The reference to the term 'mental' comes from the mental nerve which addresses the chin and lower jaw in animals. In snakes, the shape and size of this scale is sometimes one of the characteristics used to differentiate species from one another.

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Anal scale

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References

  1. Wright AH, Wright AA (1957). Handbook of Snakes of the United States and Canada. Ithaca and London: Comstock Publishing Associates. (7th printing, 1985). 1,105 pp. (in two volumes). ISBN   0-8014-0463-0.
  2. U.S. Navy (1991). Poisonous Snakes of the World. United States Government. New York: Dover Publications Inc. 203 pp. ISBN   0-486-26629-X.