The Treatise on Invertebrate Paleontology published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and covering every phylum, class, order, family, and genus of fossil and extant (still living) invertebrate animals. Part T refers to the largely extinct sea lily group. It is a revision of the original work published in 1978.
Two developments merit special attention. (1) In the 1978 edition, the Triassic forms led a modest existence. Encrinus liliiformis, one of the most common and popular crinoids, was listed with a Paleozoic ciade in Volume 2, and relationships with related taxa were not discussed. This has greatly changed, largely due to the work of Hans Hagdorn. (2) The advent of SCUBA diving, but especially the ever-increasing use of deep-sea submersibles, has led to a continuing increase in knowledge of stalked crinoids from the deep sea. As a consequence, the present revision contains much additional information on living forms that are diagnosed and illustrated accordingly.