Monday, June 18, 2012

Fictional taxa

Anyone who works with taxonomic databases is aware of the fact that they have errors. Some taxonomic databases are restricted in scope to a particular taxon in which one or more people have expertise, these then get aggregated into larger databases, which may in turn be aggregated by databases whose scope is global. One consequence of this is that errors in one database can be propagated through many other databases.

As an example (for reasons I can't remember), I came across the name "Panisopus" (in the water mote family Thyasidae) but was struggling to find any mention of the taxonomic literature associated with this name. If you Google Panisopus the first two pages are full of search results from ITIS, EOL, GBIF, ZipCodeZoo, all listing several species in the genus, and sometimes taxonomic authorities, but no links to the primary literature. If you search BHL for Panisopus you get nothing, nothing at all. It's as if the name didn't exist.

Turns out, that's exactly the point. The name doesn't exist, other than in the various databases that have consumed other databases and recycled this fictional taxon. After some Googling of author's names it became clear that "Panisopus" is probably a misspelling of "Panisopsis", which according to ION was published in:

Viets, K. (1926) Eine nomenklatorische Aenderung im Hydracarinen-Genus Thyas C. L. Koch. Zool Anz Leipzig, 66: 145--148

I can't verify this because this article is not available online. But to give one example, ITIS lists the name "Panisopus pedunculata Keonike, 1895" (TSN 83185). This name should be, as far as I can tell, Panisopsis pedunculata (Koenike, 1895), based on Mitchell, 1954 (, who on page 36 states:


Note that Panisopsis pedunculata was originally described in a different genus (Koenike 1895 preceeds the publication of the genus name by Viets in 1926). We can locate Koenike's original publication "Nordamerikanische Hydrachniden" in BHL, which I've added to BioStor, and the original description appears on p. 192 as Thyas pedunculata (note that ITIS misspells the author's name Koenike [o and e transposed], as well as omitting the parentheses around the name).

What I find a little alarming (if not surprising) is that the entirely fictional genus "Panisopus" its accompanying species have ended up in numerous taxonomic databases, and these databases consistently appear in the top Google searches for this name. The good news is that it's becoming increasingly easy to discover these errors, in part because more and more taxonomic literature is coming online, making it possible for users to investigate matters for themselves, rather than rely on unsupported statements in taxonomic databases. I'm continually amazed by how little evidence most taxonomic databases provide for any of the assertions that they make. If a database includes a name, I want some evidence that the name is "real". Show me the publication, or at least give me a citation that I can follow up. I can't take these databases on blind faith, because demonstrably they are replete with errors. Ironically, one measure of success in the Internet age is being in the top 10 hits for a Google search. Now, if the top ten hits are all taxonomic databases I get very, very nervous. It's a good sign the name only exists in those databases.