Fun with Taxonomy: Tautonymous Names

Science Ahead Warning! Much like Dr. Sheldon Cooper and his friends, the staff of MOSI Outside are dedicated geeks. We love entomology and etymology, zoology and botany and the curious naming conventions of all living things. Thus, in our geekery, we wish to give the gift of a taxonomic explanation series that we shall call: Fun with Taxonomy. 

We're awfully fun at parties. 

In an attempt to protect all brains from accidental science content, we will helpfully label all posts in this series with a tree of life image. When you see this tree, mentally prepare yourself for science content, terms with which you may not be familiar, and possibly a few history lessons. Get yourself a cup of tea and dive into some science. Now, let's have some Fun with Taxonomy!

Tautonymous Names: What's the deal with Anhinga anhinga?

Anhinga anhinga

First, a quick refresh about Binomial Nomenclature: It is the system of classification by which we scientifically name living things. The system of binomial nomenclature was developed by Carl Linneaus and it utilizes a genus and specific name or epithet to create a full scientific name for a creature. Binomial nomenclature gets us around the sticky problems of one species having many common names by providing a scientific term by which we will always know which species is being referenced.

Most of those creatures have a scientific name like:

• Lynx rufus: Bobcat
• Heliconius charithonia: Zebra Longwing Butterfly
• Fregata magnificens: Magnificent Frigatebird
• etc. etc. etc.

Sometimes, however, we find names like

• Anhinga anhinga: Snakebird, Anhinga
• Mola mola: Ocean Sunfish
• Bison bison: American Bison
• Cardinalis cardinalis: Northern cardinal

So, what's the deal with the critters with the same name twice?

Those are species with tautonymous names and the genus and specific epithet are identical. Tautonymous names will only be found within zoological nomenclature (the naming system for animals) because botanical nomenclature (the naming system for plants) specifically forbids the use of tautonymous names.

Cardinalis cardinalis

Why do they happen? Sometimes the species is the first member of a genus that has been identified. Perhaps, sometimes, a scientist was not feeling terribly imaginative and had forgotten where they last placed their Wheelock's Latin.

I have not yet found an Anhinga that complained about the lack of imagination in their binomial nomenclature, so until protests arise, this odd bit of taxonomy shall remain hidden in the corners of the internet and the back  of your brain. You might need it some day when playing trivia.

Learn More

• A fairly comprehensive list of Tautonymous Names from Wikipedia.