Related Research Articles
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 through the Lower Carboniferous (Mississippian). A possible early graptolite, Chaunograptus, is known from the Middle Cambrian. Recent analyses have favored the idea that the living pterobranch Rhabdopleura represents an extant graptolite which diverged from the rest of the group in the Cambrian. Fossil graptolites and Rhabdopleura share a colony structure of interconnected zooids housed in organic tubes (theca) which have a basic structure of stacked half-rings (fuselli). Most extinct graptolites belong to two major orders: the bush-like sessile Dendroidea and the planktonic, free-floating Graptoloidea. These orders most likely evolved from encrusting pterobranchs similar to Rhabdopleura. Due to their widespread abundance, planktonic lifestyle, and well-traced evolutionary trends, graptoloids in particular are useful index fossils for the Ordovician and Silurian periods.
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.
Anisograptidae is an extinct family of graptolites. As the first planktic graptolites, they play a crucial role for understanding the transition of graptolites from ocean floor suspension feeders to ocean surface plankton during the early Ordovician.
Sigmagraptidae is an extinct family of graptolites.
Sinograptidae is an extinct family of graptolites.
Didymograptidae is an extinct family of graptolites.
Tetragraptidae is an extinct family of graptolites from the Floian to Darriwilian epochs of the Ordovician Period.
Glossograptidae is an extinct family of graptolites.
Diplograptidae is an extinct family of graptolites.
Lasiograptidae is an extinct family of graptolites.
Climacograptidae is an extinct family of graptolites.
Dicranograptidae is an extinct family of graptolites.
Neodiplograptidae is an extinct family of graptolites.
Retiolitidae is an extinct family of graptolites characterized by meshwork-like tubaria.
Dimorphograptidae is an extinct family of graptolites.
Mastigograptidae is an extinct family of graptolites.
Cysticamaridae is an extinct family of graptolites.
Wimanicrustidae is an extinct family of graptolites.
Cyclograptidae is an extinct family of graptolites.
Axonophora is an extinct suborder of graptolites. It primarily consists of the biserial graptolites, and also includes the retiolitids and monograptids.
References
- ↑ 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.
 | This hemichordate-related article is a stub. You can help Wikipedia by expanding it. |