Submitted by AJ Cann on Fri, 25/08/2017 - 02:46

Dicranopalpus ramosus
Yet another new species?


Harvestmen, close relatives of the spiders, aren't always easy to identify to species level. Dicranopalpus ramosus has always been an exception, easy to identify from the arrangement of the long legs and the forked pedipalps. Until now...

It is often said that taxonomists can be divided into two groups - lumpers and splitters. Personally, I tend to be a lumper, partly because it makes life easier, but I'm in good company, because Darwin was a lumper. For the most part, the splitters tend to dominate though - it's easier to make a scientific living by proposing new species than it is by abolishing others. If we're citing famous naturalists, Gilbert White was a splitter - the first person to recognise that the chiffchaff, willow warbler and wood warbler were three separate species, largely on the basis of their different songs. To be a splitter these days you need a microscope, or more probably, a DNA sequencer. Which brings us back to Dicranopalpus ramosus. A new scientific paper* proposes that Dicranopalpus caudatus is a valid separate species from Dicranopalpus ramosus rather than just a different name for the same beast. Unfortunately, you can't tell the two species (which occur in the same range) apart without a microscope. 

So it looks as if we may need to start recording Dicranopalpus ramosus as "agg" - an aggregate of more than one common species where it's not possible to dissect every specimen - or as sensu lato rather than sensu stricto

Taxonomists, eh? Sigh. 


* Wijnhoven, H., & Prieto, C. E. (2015). Dicranopalpus caudatus Dresco, 1948: Not a synonym of Dicranopalpus ramosus (Simon, 1909) but a valid species after all (Arachnida, Opiliones). Revista Ibérica de Aracnología, 26, 25-34.

Thanks to Mike Higgott for pointing this out.