graptolite

[grap-tuh-lahyt]

noun

any colonial animal of the extinct class Graptolithina, most common in the Ordovician and Silurian Periods, thought to be related to the pterobranchs.

Origin of graptolite

1830–40; < Greek graptó(s) painted, marked with letters (verbal adjective from gráphein to write) + -lite

Related formsgrap·to·lit·ic

[grap-tuh-lit-ik] /ˌgræp təˈlɪt ɪk/, adjective

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Examples from the Web for graptolite

Historical Examples of graptolite

The strata consist of greywackes, flags and shales with seams and zones of graptolite shale which yield fossils sparingly.
Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1
Various

British Dictionary definitions for graptolite

graptolite

noun

any extinct Palaeozoic colonial animal of the class Graptolithina, usually regarded as related to either the hemichordates or the coelenterates: a common fossil, used to determine the age of sedimentary rocks

Word Origin for graptolite

C19: from Greek graptos written, from graphein to write + -lite

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for graptolite

1838, from Modern Latin graptolithus, literally "written-stone," from Greek graptos "engraved, written, painted" (verbal adjective of graphein; see -graphy) + lithos "stone" (see litho-). So called because the fossils resemble writing.

graptolite in Science

graptolite

[grăp′tə-līt′]

Any of numerous hemichordates of the class Graptolithina. Graptolites form colonies consisting of interlocked cuplike chambers arranged in one or more branches and covered by an exoskeleton. They flourished from the late Cambrian to the early Mississippian Period, and were thought to be extinct until 1992 when scientists discovered what is believed to be a living species. Graptolites are important index fossils used to date the rocks of the Silurian and Ordovician Periods.