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Pterygometopidae
The Pterygometopidae are a family of trilobites, that is known from the Floian to the Katian (Ordovician), and reappears from the Telychian to the Sheinwoodian (Silurian). As part of the Phacopina suborder, its members have schizochroal eyes. Distribution The Pterygometopinae may be exclusive to Baltica and are known from the Floian to the Upper Katian with 49 species in 14 genera. The 71 species from 8 genera belonging to the Eomonorachinae occur mostly in Laurentia from the Floian. One genus, '' Podowrinella'', is known from the Silurian, and may be the sister taxon of the Phacopidae. 50 species in 8 genera have been assigned to the Chasmopinae. They are exclusive to Baltica from the Darriwilian to the Sandbian. The subfamily spread to Avalonia and Laurentia in the Katian, at the end of which they became extinct. 32 species of Monorachinae in 6 genera occurred on the paleocontinent Siberia, now parts of northeastern Russia and of Alaska, from the Sandbian to the Upper Katian. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calyptaulax
''Calyptaulax'' (Cooper, 1930) is a genus of trilobites in the order Phacopida that existed during the middle and upper Ordovician in what is now the U.S. states of New York, Oklahoma, Illinois, Missouri, Virginia, Vermont, Nevada, Iowa, Wisconsin, Kentucky, and Iowa, as well as the Canadian provinces of Ontario, Newfoundland and Labrador, Quebec, and the territory of Nunavut. Other countries ''Calyptaulax'' fossils are known from include Ireland, Norway, Russia, and the United Kingdom. ''Type species'' By original designation; ''Calyptaulax glabella'' Cooper, 1930: pp. 388 - 389, pl. 5, figs. 9 - 11. From the Matapedia Group (Ashgill), Perce, Quebec, Canada. P.A. Jell and J.M. Adrain. Other species * ''Calyptaulax annulata'' Raymond, 1905[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chasmops
''Chasmops'' is a trilobite in the order Phacopida that existed during the upper Ordovician in what is now Estonia. It was described by McCoy in 1849, and the type species is ''Chasmops odini'', which was originally described under the genus ''Calymene'' by Eichwald in 1840. It also contains the species ''C. maxima''. P.A. Jell and J.M. Adrain. References External links ''Chasmops'' at the Paleobiology Database
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Achatella
''Achatella'' is a genus of trilobite in the order Phacopida, which existed in what is now Ontario, Canada. It was named by Delo in 1935, and the type species is ''Achatella achates'', which was originally assigned to the genus ''Dalmanites'' by Billings in 1860. ''Achatella'' also contains the species ''Achatella billingsi'', and ''Achatella truncatocaudata''. P.A. Jell and J.M. Adrain. References External links ''Achatella'' at the |
Bolbochasmops
''Bolbochasmops'' is a genus of trilobite in the order Phacopida, which existed in what is now Estonia. It was described by McNamara in 1980, and the type species is ''Bolbochasmops emarginata'', which was originally described as ''Chasmops bucculenta'', and later as ''Phacops bucculenta'' by Schmidt in 1881. P.A. Jell and J.M. Adrain. References External links ''Bolbochasmops'' at the Paleobiology Database
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Phacopoidea
Phacopoidea is a superfamily of trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the At ...s. External linkstrilobites.info- Gallery of Phacopida - General information- More images Arthropod superfamilies Phacopina {{Phacopida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phacopidae
Phacopidae is a family of phacopid trilobites that ranges from the Lower Ordovician to the Upper Devonian, with representatives in all paleocontinents. Description As in all Phacopina, the eyes (if present) consist of very large (0.5 mm in ''Phacops rana''), separately set lenses without a common cornea (so called schizochroal eyes). However, several phacopids have very few lenses, such as the species of the genera ''Cryphops'', ''Denckmannites'', ''Dienstina'', ''Eucryphops'', ''Nephranops'', and ''Plagiolaria'', or lack eyes altogether, like ''Afrops'', ''Dianops'', ''Ductina'', and ''Trimerocephalus''. The natural fracture lines (sutures) of the head run along the top edges of the compound eye. From the back of the eye these cut to the side of the head ( proparian) and not to the back. In front of the eye, the right and left facial sutures connect in front of the inflated glabella and consequently the free cheeks (or librigenae) are yoked as a single piece. In some of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denella
''Denella'' is a trilobite in the order Phacopida, that existed during the upper Ordovician in what is now Canada. It was described by Ludvigsen and Chatterton in 1982, and the type species is ''Denella cumera''. The type locality was the Whittaker Formation in the Northwest Territories. P.A. Jell and J.M. Adrain. References External links ''Denella'' at the Paleobiology Database
The Paleobiology Database ...
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Phacopina
The Phacopina comprise a suborder of the trilobite order Phacopida. Species belonging to the Phacopina lived from the Lower Ordovician (Tremadocian) through the end of the Upper Devonian (Famennian).Moore, R.C. (ed.). Treatise on Invertebrate Paleontology. Part O – Arthropoda (Trilobitomorpha). 1959 The one unique feature that distinguishes Phacopina from all other trilobites are the very large, separately set lenses without a common cornea of the compound eye. Habitat As far as known, all Phacopina species were marine bottom-dwellers. Origin The Early Ordovician genus '' Gyrometopus'' (superfamily Dalmanitoidea, family Diaphanometopidae) is probably close to the common ancestor of the Phacopina. ''Gyrometopus'' is phacopid in appearance, but a rostral plate is present, unlike in other Phacopina. However, the rostral plate does not divide the cephalic doublure into a left and right section, but instead the rostral suture defines a semicircle in the frontal ¾ of the doublur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phacopida
Phacopida ("lens-face") is an order of trilobites that lived from the Late Cambrian to the Late Devonian. It is made up of a morphologically diverse assemblage of taxa in three related suborders. Characteristics Phacopida had 8 to 19 thoracic segments and are distinguishable by the expanded glabella, short or absent preglabellar area, and schizochroal (Phacopina) or holochroal (Cheirurina and Calymenina) eyes. Schizochroal eyes are compound eyes with up to around 700 separate lenses. Each lens has an individual cornea which extended into a rather large sclera. The development of schizochroal eyes in phacopid trilobites is an example of post-displacement paedomorphosis. The eyes of immature holochroal Cambrian trilobites were basically miniature schizochroal eyes. In Phacopida, these were retained, via delayed growth of these immature structures (post-displacement), into the adult form. ''Eldredgeops rana'' ( Phacopidae) and '' Dalmanites limulurus'' (Dalmanitidae) are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods ( myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
