Gravicalymene
Encyclopedia
Gravicalymene is a genus of trilobites from the order Phacopida
, suborder Calymenia. Gravicalymene has been a 'hot button' trilobite lately. The species that are currently in this genus have been in Calymene
and Sthenocalymene. One thing that seems to be consistent with the genus Gravicalymene is that they sometimes occur in Dolomitic limestone
and that many occur in the Silurian
age.
The most rare example of the genus is the Middle Ordovician species Gravicalymene magnotuberculata. This species is also amongst the rarest of all Calymenidae and is regionally confined to one or two exposures in New York State. G. magnotuberculata is noted for its extremely pustulose exoskeleton, bell shaped glabella and lack of complete articulated specimens.
Phacopida
Phacopida is an order of trilobite that lived from the Ordovician to the Devonian. It is made up of a morphologically diverse group of related suborders....
, suborder Calymenia. Gravicalymene has been a 'hot button' trilobite lately. The species that are currently in this genus have been in Calymene
Calymene
Calymene is a genus of trilobites in the order Phacopida that were found throughout North America, North Africa, and Europe in primarily Silurian outcrops. Calymene are easily confused with Gravicalymene and Flexicalymene, also part of the Calymenidae family...
and Sthenocalymene. One thing that seems to be consistent with the genus Gravicalymene is that they sometimes occur in Dolomitic limestone
Dolostone
Dolostone or dolomite rock is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite. In old U.S.G.S. publications it was referred to as magnesian limestone. Most dolostone formed as a magnesium replacement of limestone or lime mud prior to lithification. It is...
and that many occur in the Silurian
Silurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
age.
The most rare example of the genus is the Middle Ordovician species Gravicalymene magnotuberculata. This species is also amongst the rarest of all Calymenidae and is regionally confined to one or two exposures in New York State. G. magnotuberculata is noted for its extremely pustulose exoskeleton, bell shaped glabella and lack of complete articulated specimens.
Species
Some known species and locations include:- Gravicalymene abbreviata (Foerste, 1910), southwestern Ohio, southeastern Indiana, and northern Kentucky.
- Gravicalymene arcuata, around Wales Great Britain.
- Gravicalymene hagani, North America
- Gravicalymene magnotuberculata, 2 localized bedding planes, New York State, United States.
- Gravicalymene truncatus, North America