ID Keys:

Lizards & Snakes

How to key


Lizards & Snakes


Cortland Herpetology Connection


These definitions will help you use the identification keys.

  • Acanthal ridges -- Ridges (with light lines) extending from the eyes to the nostrils in members of the species Gyrinophilus porphyriticus (spring salamanders).

  • Anal plate -- The scale or scales directly covering the cloaca of a snake. This plate may be single (one scale) or divided along the mid-line into two scales.

  • Bridge -- The part of the shell between the front and hind legs connecting the upper and lower halves of the shell.

  • Carapace -- The upper half of a turtle shell.

  • Costal grooves -- The grooves present along the sides of the bodies of many salamanders. When counting them for identification purposes, include only those between the front legs and the hind legs.

  • Dorsolateral ridge -- Lines or folds of skin (usually gold colored) along the upper sides of some frogs in the family Ranidae.

  • Intercalary cartilage -- An extra piece of cartilage in the toes of members of the Hylidae (tree frog) family. It causes the end of the toes to have a "stepped-down" appearance.

  • Keeled scales -- Snake or lizard scales that have a raised ridge running horizontally along each scale. They give the scales a rough appearance.

  • Keeled tail -- A salamander tail that narrows to a knife edge along its dorsal (top) surface.

  • Nasolabial grooves -- Narrow grooves that extend from the nostrils to the mouth in salamanders of the family Plethodontidae.

  • Parotoid glands -- Large skin glands that appear as swellings on each side of the back of the head of toads (family Bufonidae) and some salamanders.

  • Pit organ -- The heat sensing organs of the pit vipers that belong to the family Viperidae. They appear as holes on each side of the head between the eye and nostril.

  • Plastron -- The lower half of a turtle shell.

  • Rostral -- This is the tip of the snout.

  • Scale rows -- The scales on the bodies of snakes are arranged in rows that extend down the length of the animal. To count scale rows, choose a position about midway posterior (back) from the head. Start with the first scale row dorsal (above) the enlarged ventral (belly) scales, and count from one side of the snake over the back to the other. Do not count the ventral scales.

  • Scutes -- Another word for keratin scales. Refers especially to the keratin scales on the outer layer of turtle shells. Sometimes called horny scutes.

  • Tympanum -- This is the external ear drum visible on the side of the head of most frogs.

  • Vestigial -- Greatly reduced and non-functional.


Dr. Peter Ducey, Project Director
Biology Department, SUNY Cortland
Email: duceyp@cortland.edu
Craig Cramer, Webmaster
Email: cdcramer@clarityconnect.com

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