With nearly every new entry on this blog, I mention species, usually designated in two words such as Panorpa latipennis. The first word is actually the genus and the second is the species. The naming conventions for living things dates back to the work of Carolus Linnaeus in the 1790’s. I forget the exact year when he published his book, but he actually assigned a full name and taxonomic description to every known plant and animal.
Within the animal kingdom, Linnaeus then drilled down, getting ever more specific until every living creature could be precisely identified. A species and an animals taxonomy, however, do much more than just assure that every animal gets a unique name so that we can tell them apart. Taxonomy tells us about the relationship between each animal and the rest of the animal kingdom. It tells us what other animals have common ancestors and which share major traits.
His work stood up until around 1969 when scientists decided that simply dividing living creatures into animal and plant kingdoms wasn’t sufficient. AS M.J. Farabee tells us in his text, most now recognize five kingdoms: Plantae, Animalia, Fungi, Protista, and Monera. While the first three are obvious even to amateurs, the others are a little more obscure and generally apply to outliers from the three main groups, generally at the bacterial level, but may include single-celled organisms, multi-celled organisms, and some single-celled creatures that form colonial groups. For a little more info on these, you can click the Farabee link. Which also has some useful illustrations.
For our purposes, we’re primarily going to be dealing with the Animalia or Animal Kingdom.
From top to bottom the entire classification of an animal looks like this:
· Kingdom
· Phylum
· Class
· Order
· Family
· Genus
· Species
Formally, it’s all done in Latin, but alas, I’m not a native speaker of Latin, so I tend to fall back on English at time ;-)
So for our old friend the Scorpionfly, the entire classifications would look something like (actually exactly like - and that’s the whole point) this:
- Kingdom: Animal
- Phylum: Arthropods
- Class: Insect
- Order: Mecoptera (or Scorpionflies, Hanging flies and Allies)
- Family: Panorpidae (or Common Scorpionflies)
- Genus: Panorpa
- Species: latipennis (or commonly -Panorpa latipennis)
At the species level, there is no other creature with the same designation, but as we climb the classification tree, each level includes more and more relatives. The Genus Panorpa, as we know contains 40 species of scorpionflies that live in North America. When we get to Class, all insects are included. The Phylum Arthropods includes all insects, spiders, crustaceans, and other creatures having an exoskeleton. One step higher up and we include all animals.
By knowing the taxonomic hierarchy, we can immediately communicate some information about almost any creature I am likely to find in my yard. If it has an exoskeleton, I know right away that it’s an arthropod. If it further has three body segments, three pairs of legs, compound eyes and two antennae, I know it’s an insect.
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| Scorpionfly (Panorpa latipennis) Photo by Brad Sylvester, copyright 2011, all rights reserved |
Without at least this basic level of subdividing animals into groups, it would be much harder to figure out what each creature really is. By narrowing it down to insects, I know where to concentrate my search. As I get closer and closer, the search narrows even more. For example, in the case of our scorpionfly, I could rule out a number of orders right away. It’s clearly not a beetle, butterfly, or millipede, so I don’t need to search through those listings.
It looks something like a wasp or a specialized fly, leaning toward the fly because I don’t see a wasp-like narrow waist. So I choose to start with flies. From there, for me, it’s a matter of flipping through field guide images to find something similar. I may not find the exact match, but I’ll generally get to the Family or Genus level and from there I can use web references to drill down to a more exact match.
To determine an exact match, you want to not only compare photos, but also look at identification marks. These are (hopefully visible) traits that are specific to this one species. Photos can be a little deceptive, especially if they are taken at different angles, in different lighting, or of individuals with some variance to the one you’ve found. The species identification points, however, should be exact, although there are some that simply can’t be determined with a visual examination or require an in-hand examination with magnification. In these cases, you might look at range or behavior as additional clues.
When all else fails, ask someone with more skill that you have. Try the entomology department at your local college or university for starters.
The classification or taxonomy system allows us to more quickly identify a living creature, by ruling out large blocks of creatures and narrowing down our search to relevant candidates with relatively little effort. It’s as if every living creature were neatly filed away on a library shelf and the system of taxonomy is the index card file that lets us find each one.
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