These little guys are Maratus volans, a species in the peacock spider genus. When I say little I mean it -
I'm not usually a big arachnid person.. I'm a little scared when I encounter a big spider in my basement... but as a class of animal I think they're fascinating. So lets break down the arachnids just a little before we dive into the dancing peacock spiders!
Spiders have a hard outside and squishy insides - we've all stepped on a spider before right? Simply put, having a hard outside - an exoskeleton - makes spiders Arthropods. Arthropods are a huge group of animals that have exoskeletons (no bones on the insides, just hard outsides made of chitin and protein), segmented bodies, and jointed limbs. Arthropods include everything from crabs, to shrimp, barnicles, crickets, centepedes, scorpions, and spiders. A HUGE group right?? This huge group is called a Phylum.
So the huge Phylum Arthropoda gets broken down into more "like" groups. Our next breakdown is a grouping of the horseshoe crabs and other slightly spooky critters like spiders, scorpions and ticks. They all have appendages that appear before the mouth called "chelicerae". These chelicerae (mouth parts) are usually small pincers. This slightly smaller group is called the Chelicerata and we refer to it as a Sub-Phylum.
Now we get to the good stuff. Our next "like" group is all the chelicerates with eight legs - arachnids! So we've cruised from Phylum Arthropoda; segmented bodies with crunchy outsides, to Subphylum Chelicerata; crunchy critters with mouth appendages, to Class Arachnida; creatures with all of the above who have eight legs. Arachnids are spiders, scorpions, mites, ticks, and solifuges.
We're interested in just the spiders today. So our final stop is the Order Araneae; segmented, crunchy critters with eight legs and mouthbits - but the mouthbits (chelicerae) must be fangs to be in this group. That's what makes a spider an araneid, is having ALL of these characteristics. If a creature is segmented, crunchy, has eight legs and mouthbits BUT THE MOUTHBITS ARE NOT FANGS then it is not an araneid/spider. Make sense?