Velvet Worm Brains Reveal Secret Sisterhood With Spiders

Onychophora (Velvet Worms) live in groups, defend territories and subdue their prey with sticky goo. The small, sometimes brightly colored, worm-like carnivorous creatures have lobed appendages and live in leaf litter in tropical areas.

"They are very difficult to approach with a pair of forceps because they squirt out this gluey substance that bungs up one's dissection tools. In the wild they use it to immobilize their prey," Strausfeld said of the 2-inch-long critters. "They're really quite extraordinary."

Strausfeld and his colleagues compared the brain architecture of onychophorans with a range of arthropods, including spiders, scorpions, dragonflies, bees, crabs, shrimps and centipedes.