Friday, October 16, 2015

How do you know a species is new to science?

Students often ask me, how does one go about a describing a new species? It's easy, you just have to know what has been described before! I am kidding, of course. Knowing what has been described before is by far the hardest part of describing a new species.

Here is an example: I work with a group of rove beetles belonging in the subtribe Xanthopygina, a group of 30 or so genera and ~400 species. To be able to describe a new species with confidence, I need to know how all 30 genera and all 400 species look like. Why? Because the generic limits that we recognize today might have been more relaxed in previous years, and species currently in one genus might actually belong in another (this has happened multiple times to me in the past). So if somebody wants to describe new species in e.g. the genus Plociopterus Kraatz, seeing just the existing species in Plociopterus is not good enough. People of course describe like that all the time (or by just finding a species in a "new area"), but this leads to sloppy (at best) taxonomic work.

Over the past few years I have been working with myrmecophile Xanthopygina. One of the most prominent early 20th century myrmecophile entomologist was Wasmann. His collection ended up in Maastricht and this week I was able to finally see all of the Xanthopygina species he described.

This post-it note was glued on my monitor for the last three years. A constant reminder that there were still species described in Xanthopygina that I had not seen. But now this over and I feel much better describing new species that are in or close to Plociopterus. And I have to say, I did get rewarded for insisting to see these species: one of the two  both species described by Wasmann probably belong in a different subtribe altogether.