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The timber rattlesnake, canebrake rattlesnake or banded rattlesnake, is a species of venomous pit viper endemic to eastern North America. This is the only rattlesnake species in most of the populous northeastern United States and is second only to its cousins to the west, the prairie rattlesnake, as the most northerly distributed venomous snake in North America. No subspecies are currently recognized.
Crotalus helleri is a highly venomous pit viper subspecies found in southwestern California and south into Baja California, Mexico.
Ophryacus is a genus of venomous pit vipers endemic to Mexico. The name is derived from the Greek word ophrys, which means "brow", and the Latin word acus, which means "needle", an allusion to the characteristic horn-like scales over the eyes. Currently, three species are recognized and no subspecies.
Crotalus viridis nuntius is a venomous pit viper subspecies native primarily to the desert plateau of the northeastern portion of the American state of Arizona, but also ranges into northwestern New Mexico. Named for the Native American Hopi tribe, which inhabits the region, its range overlaps that of the nominate subspecies and some interbreeding is believed to occur. The taxonomy of the C. viridis group is a matter of debate, many considering the various subspecies to be nothing more than locality variations.
In snakes and amphibians, the canthus, canthal ridge or canthus rostralis, is the angle between the flat crown of the head and the side of the head between the eye and the snout, or more specifically, between the supraocular scale and the rostral scale. It is defined as a sharp ridge in many viperids, but is rounded in most rattlesnakes, for example.
The labial scales are the scales of snakes and other scaled reptiles that border the mouth opening. These do not include the median scales on the upper and lower jaws. The term labial originates from Labium, which refers to any lip-like structure. In snakes, there are two different types of labial scales: supralabials and sublabials. The numbers of these scales present, and sometimes the shapes and sizes, are some of many characteristics used to differentiate species from one another.
In reptiles, the nasal scale refers to the scale that encloses the nostril.
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.
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.
In scaled reptiles, the ocular scales are those forming the margin of the eye. The name originates from the term oculus which is Latin for "eye" and, in the broadest sense, refers to a scale associated with the eye. The numbers of these scales present, and sometimes the shapes and sizes, are some of many characteristics used to differentiate species from one another.
In reptiles, the supralabial scales, also called upper-labials, are those scales that border the mouth opening along the upper jaw. They do not include the median scale. The term labial originates from Labium, which refers to any lip-like structure. The numbers of these scales present, and sometimes the shapes and sizes, are some of many characteristics used to differentiate species from one another.
In reptiles, the sublabial scales, also called lower-labials or infralabials, are those scales that border the mouth opening along the lower jaw. They do not include the median scale. The term labial originates from labium, which refers to any lip-like structure. The numbers of these scales present, and sometimes the shapes and sizes, are some of many characteristics used to differentiate species from one another.
In snakes, the internasal scales are those on top of the head between the scales that surround the nostrils. They are usually paired and situated just behind the rostral.
In snakes, the anal scale is the scale just in front of and covering the cloacal opening. This scale can be either single or paired. When paired, the division is oblique. The anal scale is preceded by the ventral scales and followed by the subcaudal scales.
In snakes, the subcaudal scales are the enlarged plates on the underside of the tail. These scales may be either single or divided (paired) and are preceded by the anal scale.
In reptiles, occipital scales are enlarged plates that lie directly behind the parietal scales.
In snakes, the interorbital scales, or intersupraoculars, are the scales on the top of the head between the plates surmounting the eyes.
Crotalus oreganus is a venomous pit viper species found in North America in the Baja California Peninsula, western United States, and southern interior of British Columbia.
Crotalus cerastes laterorepens, with the common name Colorado Desert sidewinder, is a venomous pitviper subspecies found in an area that centers on the Sonoran Colorado Desert in Southern California. It is also native to the Sonoran Desert in the Southwestern United States and Northwestern Mexico.
In snakes, intercanthals are scales on top of the snout located between the canthal scales.
References
- 1 2 3 Campbell JA, Lamar WW. 2004. The Venomous Reptiles of the Western Hemisphere. Comstock Publishing Associates, Ithaca and London. 870 pp. 1500 plates. ISBN 0-8014-4141-2.
- ↑ Wright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates. (7th printing, 1985). 1105 pp. ISBN 0-8014-0463-0.
- This article incorporates material from the Citizendium article "Canthal scales", which is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License but not under the GFDL.
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