Monograptus

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Monograptus
Temporal range: Lower Devonian
Spirograptus spiralis.jpg
Monograptus spiralis
Scientific classification
Kingdom: Animalia
Phylum: Hemichordata
Class: Graptolithina
Order: Graptoloidea
Family: Monograptidae
Genus: Monograptus
Geinitz, 1852

Monograptus is a genus of graptolites in the Order Graptoloidea. This particular genus is the last stage of the graptoloid evolution before its extinction in the early Devonian. A characteristic of the genus includes one uniserial stipe with very elaborate thecae. This particular genus contains large number of graptolite species and may not be monophyletic.

Biostratigraphic significance[edit]

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 Devonian.[1] 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.

References[edit]

  1. ^ Gradstein, F. M. et al. ICS on Stage, page 5. Retrieved 2015-06-16.

External links[edit]

  • Photo; Article english.fossiel.net—"graptolite Monograptus from Bornholm, Denmark"