Lizards & Snakes
How to key
Lizards & Snakes
Cortland Herpetology Connection
How to use the identification keys
The usefulness of the Amphibian and Reptile Atlas depends on its accuracy.
It is essential that each animal you report is accurately identified. But
that's not too hard using the identification keys we provide.
keys are called dichotomous keys. At each step of the key you compare two
descriptions to see which best fits the animal you are identifying. Then you go
on to another choice until you've identified the animal.
suppose you are holding some kind of reptile or amphibian from New York and
wanted to classify it in the correct group (frogs, salamanders, snakes and
lizards, or turtles). You could use the following key. Start at Step 1, below.
||Has external gills
||No external gills
This step means that if your animal has external gills (line 1.a.), then it
must be a salamander, and you now know in which of the groups your animal
belongs. If you click on the linked text "salamander,"
your browser will take you to the detailed key to salamanders. If your animal
lacks external gills (line 1.b.), then go to Step 2. If you click on the
2, you'll jump down to the next step in the key.
||Has scaly skin or a shell
||Has neither scaly skin nor a shell
In other words, if it has scales or a shell go to Step 3.
If not, jump to Step 4.
Again, clicking on turtle will take you to the
turtle key, and clicking on lizards and snakes will
take you to the lizard and snake key.
When you go to the key for each major group (frogs,
salamanders, turtles, or
lizards and snakes) you should start with the key to
the families at the top of the page. This will tell you the name of the family
in which your animal belongs.
Then you'll jump down the page by
clicking on the family name to the key for the members of that family to
determine the correct name for the species you are identifying. In the species
keys, we provide common and scientific names. Click on the name and see a
picture of the animal. (If the name isn't linked, that means we don't have a
picture of that species yet.)
Some of the terms used in the keys that
might be unfamiliar to you are linked to definitions in the
glossary. For example in the salamander key you'll
Clicking on costal grooves will take you
to that entry in the glossary. Use the back button on your browser to return to
the key. Most browsers will return you to the exact spot in the key where you
were. With others you may find yourself dropped off somewhere else in the key.
your time when using the keys to get a correct identification. If you don't
understand a particular term or can't tell if your animal has this trait, check
the definitions we provide, look in the books we've sent, or email
firstname.lastname@example.org with your
Remember the accuracy of the Atlas depends on you making the
Special thanks to all those who generously loaned images and other
help. See our
credits page for more information.