One of the questions I am asked most often during presentations and workshops is, “what is the difference between a turtle and a tortoise?” Or for that matter, what is the difference between frogs and toads, and newts vs. salamanders? These questions are sort of like being asked what the difference is between sports and baseball. Baseball is a sport, but not all sports are baseball. Similarly, tortoises are just a group of closely-related land-dwelling turtles that happen to have common names ending in tortoise rather than turtle (one out of 14 turtle families that are alive today). Similarly, toads are just different kinds of frogs that, while not all closely related to one another, have drier skin than most other frogs and tend to produce toxic secretions. And newts are just salamanders belonging to a single family that, for whatever reason, are called newts instead of salamanders. All tortoises are turtles, but not all turtles are tortoises, as is also the case with toads compared to frogs and newts to salamanders. That’s the short answer. If you want the detailed answer, keep reading. Let’s start with turtles.
In taxonomy, the basic unit that we think of most often is the species. Although defining what a species is gets complicated very quickly, I generally think of species as groups of animals adapted to seek each other out for the purpose of mating and that are capable of producing fertile offspring that look and behave similarly to their parents (though this definition disregards species that do not mate). A genus is a group of species very closely related to one another, many of which may be difficult to distinguish to the untrained eye. Families are groups of genera (plural of genus) that share a common ancestor, and orders are groups of related families. Of course it is much more complicated than that, but orders are where distinguishing between the different groups becomes pretty easy, even to the untrained eye. Frogs are an order. Turtles are an order. Lizards (including snakes) are an order. When it comes to reptiles and amphibians, for the most part, all you need to do is take one look at an animal to know what order it belongs to (although there is some confusion about salamanders and lizards due to their similar body shapes). With birds and mammals, you need to know a thing or two to determine the order, but it still isn’t rocket science (insects are a different story).
In the United States we have six different families within the turtle order, most being comprised of many species, all of which are as much of a turtle as any other; Sea Turtles, Snapping Turtles, Pond and Box Turtles (which includes things like Sliders, Cooters, Terrapins, Box, and Wood Turtles), Mud and Musk Turtles, Softshell Turtles, and of course, Tortoises. You may hear that the main difference between a turtle and a tortoise is that turtles live in water and tortoises live on land. While that, as a general rule, has some basis in reality (tortoises do live on land), there are lots of examples of fully terrestrial turtles that are not in the tortoise family. Box Turtles are the most obvious example, and although they have highly domed shells like tortoises and are very poor swimmers, they are much more closely related to an aquatic Painted Turtle than they are to a tortoise. Likewise, if you look to Central and South America, some species of Ornate and Painted Wood Turtles (in yet another turtle family) are quite terrestrial, and in Eurasia there are other types of Box Turtles, unrelated to those in North America, that also live entirely on land. Another species, the Tricarinate Hill Turtle, roams the forests and savannahs of India, Bangladesh, and Nepal. Those are just a handful of examples. If the word “tortoise” did not exist and they were called turtles instead (as they are in other languages), there really wouldn’t be a question to ask. So, tortoises are fully terrestrial turtles that have highly domed shells and all belong to a single taxonomic family, but they are not the only terrestrial turtles. Feel free to refer to tortoises as turtles whenever you like, but be prepared to defend your use of the word “turtle” (and remember it’s not something worth getting into an argument over).
With toads the answer is almost as cut and dry, except there are several different families of frog containing species called toads. In North America, that includes what are considered “true” toads in the Bufo/Anaxyrus genus (those are the ones with very dry, bumpy skin and large toxic glands at the base of their skulls such as American Toads and Fowler’s Toads), but we also have Narrow-mouthed Toads and Spadefoot Toads, each in their own families, and not even closely related to the others. If you lumped all toads together in one group, that would be akin to taking all terrestrial turtles, regardless of what family they are in, and calling them all tortoises, which would have been fine if that’s how they were named because until recently there weren’t many guidelines for common names. Still, it is helpful to at least understand how these animals relate to one another.
In the case of newts and salamanders, things are actually a little backwards when it comes to their common names. Newts, which are characterized in part by having rough, toxic skin, are in the Salamandridae family of salamander, also referred to as “true salamanders”. Within that family, some species are called newts and others are salamanders, mostly split along wet skin vs. dry skin lines, but to the best of my knowledge, no salamanders from any other family are called newts. In North America, those other salamander families include the mole salamanders (ie: Spotted and Tiger Salamanders), lungless salamanders (such as Slimy and Red-backed Salamanders), and waterdogs (Mudpuppies), to name a few. So again, similar to what we have with tortoises and toads, all newts are salamanders, but not all salamanders are newts.
The bottom line here is that common names can be confusing, and sometimes include relics from the early days of taxonomy when the relationships between different groups of animals were not as well known. While there are accepted common names that are used in literature (this being the most widely accepted list), nomenclature falls apart very quickly when you start considering all the local names people use for these animals. To some, Hellbenders, which are massive aquatic salamanders with wrinkly skin, are known as “snot otters”, and if you head to rural parts of the southeastern US, salamanders in streams are called “spring lizards”. Wherever you go, you are sure to find that people in that area will refer to some species by odd names that appear almost nowhere in the literature. It’s certainly not worth getting into arguments over common names, but knowing what the accepted common and scientific names are can at least help two people figure out which species the other is talking about. Since we get asked so often what the difference is between these different animals, we thought it helpful to provide a fairly thorough answer, so enjoy your new-found information and get ready to ace your next trivia night!