Encrinites are a type of
grain-supported bioclastic
sedimentary rock in which all or most of the grains are
crinoidossicles. In older literature, the word is sometimes used to refer to individual fossil
crinoids, but this usage is obsolete.
Distribution
Encrinites form in areas where disaggregated crinoid skeletal debris becomes concentrated, typically shallow warm euhaline seas. They are therefore very common in the
Paleozoic rock record of North America and Eurasia, particularly during the
Silurian through Early
Devonian and the Early
Mississippian age, when high sea levels created widespread
epeiric seas. Some encrinites are also known from the
Jurassic of North America and Western Europe.
References
Ausich, W.I. 1997. Regional encrinites: a vanished lithofacies. In: Paleontological events: stratigraphic, ecologic and evolutionary implications, p. 509–519. Columbia University Press, New York.
Hunter, A.W. and Zonneveld, J.P. 2008. Palaeoecology of Jurassic encrinites: reconstructing crinoid communities from the Western Interior Seaway of North America. Palaeogeography, Palaeoclimatology, Palaeoecology 263: 58–70.