''Monograptus'' is a genus of graptolites in the Order Graptoloidea. This particular genus is the last stage of the

graptoloid Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian (Miaolingian, Wuliuan) through th ...

evolution before its extinction in the early

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

. A characteristic of the genus includes one uniserial stipes with very elaborate thecae. This particular genus contains large number of graptolite species and may not be

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

Biostratigraphic significance

The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum (FAD) of ''Monograptus uniformis'' as the defining biological marker for the start of the Lochkovian, 419.2 ± 3.2 million years ago, the earliest stage of the

.Gradstein, F. M. et al. ''ICS on Stage''
page 5. Retrieved 2015-06-16. ICS has assigned the FAD of ''Monograptus parultimus'' defining biological marker for the start of the Pridoli epoch, 423.0 ± 2.3 million years ago, of ''Monograptus turriculatus'' (together with the replacement of the brachiopod '' Eocoelia intermedia'' with '' E. curtisi'') for the start of the Telychian, 438.5 ± 1.1 million years ago, and of ''Monograptus austerus sequens'' for the start of the Aeronian, 440.8 ± 1.2 million years ago, all stages of the

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...

References

External links

PhotoArticle
english.fossiel.net—"graptolite ''Monograptus'' from Bornholm, Denmark" Graptolite genera Silurian animals Graptoloidea Index fossils Fossils of Algeria Fossils of Sweden Paleozoic life of British Columbia Paleozoic life of the Northwest Territories Paleozoic life of Nunavut Paleozoic life of Quebec Paleozoic life of Yukon {{devonian-animal-stub