I've just had a paper out. The funny thing is, it's making me feel both pleased yet a little maudlin, because it represents something of an end of an era. The last part of my PhD thesis has been published. The last remnant of my student days has been cast off. I think I need a hug.
The paper in question is: Taylor, C. K. 2013. Further revision of the genus Megalopsalis (Opiliones, Neopilionidae), with the description of seven new species. ZooKeys 328: 59-117. It's open access, so go take a squizz. One thing that I also can't resist pointing out, though I don't know if it really makes much difference because it's a primarily online journal and hardly anyone will see the print issue: it's one of my images on the cover.
Technically, this paper represents my long-awaited (by me, at least) revision of the harvestman genus Spinicrus. In the end, though, I had to change the title of the paper, because on of the main results of this revision was that Spinicrus became a synonym of the older genus Megalopsalis. In an earlier publication, I cut Megalopsalis down to size by removing its New Zealand species to a new genus, Forsteropsalis. But now it's back, and stronger than ever before!
Previously, Spinicrus was primarily separated from Megalopsalis by one feature: the presence of a side branch on one of the segments of the pedipalps of Megalopsalis. Taxonomists tend to be wary of defining a group purely by the absence of features. It implies that the members of that group are united more by the idea that they just don't belong in any other group, rather than anything that actually connects them per se. So, in this case, Megalopsalis was the species with a pedipalp side-branch, and Spinicrus was... the rest. It also didn't help matters that a pedipalp side-branch is something that has evolved and de-evolved a number of times within harvestmen, leading to a bit of questioning about its significance. A few years ago, I separated a few of the more distinctive 'Spinicrus' as the genus Neopantopsalis. This made Spinicrus a bit less heterogeneous but still didn't solve the underlying issue. It just meant that now you took out Megalopsalis and took out Neopantopsalis, and Spinicrus was still... the rest.
The answer, as so often in invertebrate taxonomy, came largely from the boy bits. When I looked at the male genitalia, I found that Megalopsalis and Spinicrus species shared a similar penis morphology, in which the end of the penis was fairly short, flat and shaped more or less like a rounded triangle:
In contrast, the end of the penis in Neopantopsalis species is longer, as demonstrated by N. thaumatopoios:
Put these features into a phylogeny of the family that these genera belong to (Neopilionidae), and I overall ended up with this:
Note that this is a bit of a faux phylogeny, because it's a comparative summary of separate analyses under separate parameters (see the paper for details). Only those clades marked with a 100 were supported in all analyses. The important detail is the distribution of the green 'Spinicrus' relative to the red 'Megalopsalis': no matter what the analytical conditions, 'Megalopsalis' was always nested well within 'Spinicrus'. Indeed, under most conditions, 'Megalopsalis' was polyphyletic within 'Spinicrus'. Because of this, and because of the lack of any positive uniting features for Spinicrus species that were not also present in Megalopsalis, I felt the best course of action was to declare the two genera synonyms. Also subsumed under Megalopsalis was Hypomegalopsalis, a species that I had earlier established for a single species of uncertain affinities (Megalopsalis tanisphyros in the tree above). At the time, I commented that, "if anyone conducts a further study in the future that supports quashing Hypomegalopsalis, I won't be protesting". The fact that I got to do that myself just makes me all the happier.
There's a lot more I could talk about here, but I'm sure you all stopped reading long ago. Just go to the paper.