The great marine blog Deep Sea News has a post up about Pycnogonids, or sea spiders. These bizarre and fascinating Chelicerates are distantly akin to horseshoe crabs and arachnids. However, there is some contention about weather Pycnogonids reside within Chelicerata, or represent a distinct sister subphylum. Learn more about them in the following links:
- Deep Sea News overview
- Slideshow showing sea spiders feeding on anemones, at Science
- In depth overview with many references, from the AAS
Modern (left) and fossil (right) pycnogonids. The fossil is from the Devonian, roughly 400 mya. Photos from Daniel Swezey (MBARI) and the Berkeley Paleontology Museum.