On the weekend, our #Mexigonus2017 jumping spider expedition stumbled on many bell-bottom pants, but not the kind you’re thinking of. After leaving Ixtlán, we drove south to San José del Pacifico, a little town in the Sierra Madre del Sur mountain range famous (so it seems) for its interesting mushrooms. Around our little cabin in the oak-pine forest at 2500 metres elevation, and then along our hike up the hill behind it, we found three different species of Mexigonus whose males have fringes of black hairs on either side of their first legs. It makes the legs look much thicker than they are, giving the illusion of bell-bottom pants.
The next day we found two more fringed species, giving a total of 5. Here they are:
Mexigonus species with fringes on the sides of the first pair of legs
OK, maybe they don’t look like bell-bottom pants to you. The fringes don’t actually get wider toward the tip (like a true bell-bottom), but rather they don’t taper as much as normal, so (to someone who is used to seeing spider legs taper) it seems as if they are getting wider. Believe me.
Here is another view of the five species, in the same sequence as above:
Same Mexigonus species with lateral fringes on the first pair of legs
What’s strange is that we didn’t find any species with lateral fringes in the mountain range north of Oaxaca city. Is there a local diversification of them in the Sierra Madre del Sur?
By the way, all 5 of these species appear new to science.
Reflections on a Spider's Eyes 