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Graptolithina is a subclass of the class Pterobranchia, the members of which are known as graptolites. These organisms are colonial animals known chiefly as fossils from the Middle Cambrian through the Lower Carboniferous (Mississippian). A possible early graptolite, Chaunograptus, is known from the Middle Cambrian. One analysis suggests that the pterobranch Rhabdopleura represents extant graptolites. Studies on the tubarium of fossil and living graptolites showed similarities in the basic fusellar construction and it is considered that the group most probably evolved from a Rhabdopleura-like ancestor.
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Monograptidae is an extinct family of graptolites of the Order Graptoloidea. Monograptids have only one row of thecae per stipe, unlike the biserial graptolites which have two opposing rows of thecae per stipe.
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Tetragraptidae is an extinct family of graptolites from the Floian to Darriwilian epochs of the Ordovician Period.
Glossograptidae is an extinct family of graptolites.
Dicranograptidae is an extinct family of graptolites.
Normalograptidae is an extinct family of graptolites.
Neodiplograptidae is an extinct family of graptolites.
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Dendrograptidae is an extinct family of graptolites.
Acanthograptidae is an extinct family of graptolites.
References
- 1 2 Maletz, Jörg (2017). Graptolite Paleobiology. Wiley-Blackwell. ISBN 9781118515617.
- ↑ Maletz, Jörg (2014). "The classification of the Pterobranchia (Cephalodiscida and Graptolithina)". Bulletin of Geosciences. 89 (3): 477–540. doi: 10.3140/bull.geosci.1465 . ISSN 1214-1119.
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