What does crinoidal mean?
Crinoidal is an adjective of geology and palaeontology describing rocks — most often limestones — that are composed of or contain abundant fragments of crinoids, the marine animals popularly known as sea lilies. Because crinoids possessed skeletons of numerous small calcareous plates that readily broke apart after death, their scattered remains can accumulate in vast quantities on the seabed, eventually forming distinctive crinoidal limestones recognizable by their speckled, fragmentary texture. The word also applies more broadly to anything relating to or characteristic of crinoids themselves. It appears almost entirely in technical literature, field guides, and museum contexts rather than everyday speech, and it is neutral in tone. The word is valuable because it names a specific and widely occurring rock type: many celebrated building stones marketed as marbles are actually crinoidal limestones, giving the term practical relevance to architecture and heritage as well as to science.
Composed of or containing abundant fragments of crinoid skeletons, especially said of sedimentary rocks such as limestone.
"The bridge piers were cut from local crinoidal limestone."
Chiefly used in geology and palaeontology.
Relating to or characteristic of crinoids.
"The bed shows a crinoidal assemblage typical of open-marine conditions."
Some of Britain's finest 'marble' fireplaces aren't marble at all — they're crinoidal limestone built from millions of broken sea-lily skeletons that lived hundreds of millions of years ago.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of crinoidal
Crinoidal derives from crinoid, which comes via New Latin Crinoidea from the Greek 'krinon', meaning lily — a reference to the flower-like form these echinoderms were thought to resemble. The suffix '-al' simply forms an adjective from the noun. The term arose with nineteenth-century geological description of fossil-bearing limestones, when crinoid-rich beds were being systematically named and classified.
How crinoidal is actually used
A technical term used almost exclusively in geology, palaeontology, and related earth sciences; rarely encountered in general conversation. It carries no emotional connotation and is neutral in register.
Easily confused with crinoidal
Cricoid refers to the ring-shaped cartilage of the lower larynx, while crinoidal describes rock or material made of crinoid (sea lily) remains.