Hey, good call on the Gonyleptidae but I believe it is actually a Cosmetidae. Of course it is impossible to tell without counting tarsal segments but it looks like a Cosmetid, despite the spines that are often seen in Gonyleptidae.
Yeah, I was looking at the spines, but also the large body size relative to the leg length, and the thick fourth legs. Also, the conspicous palpi that don't look flattened as they are in Cosmetidae.
However, I didn't know about the tarsal segment count. Is it higher with Gonyleptidae?
I was looking at Wikipedia and they mentioned the Gonyleptidae sub-familily Pachylinae, with 400 species. Cosmetidae has over 700, and Gonyleptidae over 800. That's a LOT of species!!! And, they're all new world and mostly in South America, with Cosmetidae having the greatest representation in Central and North America.
I have something that looks like that around my home. I always wondered what they were but I never even knew where to start trying to ID them. They are really bizarre little creatures and I usually see them alone.