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Any of numerous extinct colonial marine animals chiefly of the orders Dendroidea and Graptoloidea of the late Cambrian to the early Mississippian Periods, whose fossil remains are often used to date the rocks of the Silurian and Ordovician ages.

[Greek graptos, written (from graphein, to write; see graphic) + -lite (from the resemblance of the fossils' impressions on shale to markings on a slate).]


(Palaeontology) 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
[C19: from Greek graptos written, from graphein to write + -lite]


(ˈgræp təˌlaɪt)

any extinct marine animal of the class Graptolithina that grew in branching, floating colonies preserved as traces in Ordovician through Mississippian deposits.
[1830–40; < Greek graptó(s) painted, marked with letters (v. adj. of gráphein to write) + -lite]
grap`to•lit′ic (-ˈlɪt ɪk) adj.
References in periodicals archive ?
Alum shale as well as Estonian graptolite argillite (GA) contains remarkably high concentrations of trace metals such as U, Mo, V and Ni, but may also be locally enriched with REE, Cd, Au, Sb, As and Pt.
Les parties superieures de la Formation de Bear River dans le secteur nord-ouest et la Formation de Feltzen dans les secteurs sud-est contiennent par endroits le graptolite Rhabdinopora flabelliformis du debut de l'Ordovicien, ce qui porte a croire que les Formations sous-jacentes d'Acacia Brook, de Cunard, de Bloomfield et de Moshers Island dateraient du Cambrien moyen au Cambrien tardif et qu'il y aurait une discordance importante entre le group de Halifax et la Formation de White Rock sus-jacente, qui date du Silurien.
In Estonia the Lower Ordovician succession is represented by quartzose sandstones of the Kallavere Formation, dark laminated graptolite argillites of the Turisalu Formation, and light claystone of the Varangu Formation of the Tremadoc Age, followed by glauconitic silts, sands or calcareous sandstones of the Leetse Formation, and glauconitic limestones of the Toila Formation of the Arenig Age (Mannil & Meidla 1994).
The studies of two vertical sequences of graptolite argillite (GA) show the existence of pronounced fine-scale trace metal variability in GA.
Thus, the base of the Sixth Stage of the Ordovician System correlates with the lower to middle part of the Keila Stage in Baltoscandia, and is in close proximity to the foliaceous/clingani graptolite zonal boundary.
Restudy of graptolite collections of Decker (1942, 1952) from nearby wells in Crane County, Texas, indicates that dark shales (Frame Member) previously assigned to the Silurian, range from the Ludlovian (Silurian) into the Pragian (Early Devonian).
3]) was observed when the soil with a background eU concentration was overlain by a dense and thick (> 20 cm) humus horizon and there existed an additional inflow of Rn from graptolite argillite and obolus phosphorite lying at a depth of 65-75 m.
Metallogenesis of early Paleozoic graptolite shales from the Graefenthal Horst (Northern Bavaria-Federal Republic of Germany): Economic Geology, 81, 889-903.