The caryophylliines are known from the early Jurassic (180 million years ago) to the Recent, and occur in most marine environments to a depth of 3200 m. They are an extremely diverse group, consisting of 91 living genera and 457 living species (Cairns et al., 1999). Although some species form large colonies that may contribute to both shallow-water and deep-water reef/bank structure, most members of this suborder are small (less than 30 mm) and inconspicuous, occurring in cryptic shallow-water environments or in cold (as low as -1°C), dark, deep waters. Although several other scleractinian families occur in deep water (e.g., Dendrophylliidae, Micrabaciidae, Fungiacyathidae), the caryophylliines have been the most successful in exploiting the deep-sea realm. Because many occur below the euphotic zone or cryptically in shallow water, most species are azooxanthellate (do not contain symbiotic unicellular dinoflagellates) and therefore rarely attain a large size.