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Pterygotioidea
Pterygotioidea (the name deriving from the type genus ''Pterygotus'', meaning "winged one") is a superfamily of eurypterids, an extinct group of aquatic arthropods. Pterygotioids were the most derived members of the infraorder Diploperculata and the sister group of the adelophthalmoid eurypterids. The group includes the basal and small hughmilleriids, the larger and specialized slimonids and the famous pterygotids which were equipped with robust and powerful cheliceral claws. Though the more primitive hughmilleriids were small, '' Hughmilleria wangi'' being the smallest of all pterygotioids at just in length, later members of the group, particularly in the Pterygotidae, would become the largest known arthropods to ever exist with several genera surpassing in length. Among all currently recognized eurypterid clades, the Pterygotioidea is the most diverse, containing over 50 species in 10 genera. With the number of recognized eurypterid species being around 250, pterygotio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hughmilleria
''Hughmilleria'' is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of ''Hughmilleria'' have been discovered in deposits of the Silurian age in China and the United States. Classified as part of the basal family Hughmilleriidae, the genus contains three species, ''H. shawangunk'' from the eastern United States, ''H. socialis'' from Pittsford, New York, and ''H. wangi'' from Hunan, China. The genus is named in honor of the Scottish geologist Hugh Miller. ''H. socialis'' is the type species of Hughmilleriidae, a eurypterid family classified in the superfamily Pterygotioidea that is differentiated by their streamlined bodies, the enlargement of their medium-sized chelicerae and the presence of paired spines on the walking appendages. With the biggest specimen measuring 20 centimetres (8 inches) in length, ''Hughmilleria'' is considered a eurypterid of small size. Description ''Hughmilleria'' is the most basal (primitive) known member of the Pterygotioidea. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adelophthalmoidea
Adelophthalmidae (the name deriving from the type genus ''Adelophthalmus'', meaning "no obvious eyes") is a family of eurypterids, an extinct group of aquatic arthropods. Adelophthalmidae is the only family classified as part of the superfamily Adelophthalmoidea, which in turn is classified within the infraorder Diploperculata in the suborder Eurypterina. Adelophthalmid eurypterids were small and swimming eurypterids that appeared in the Silurian period. With the earliest known members of the group, '' Nanahughmilleria prominens'' and '' Parahughmilleria maria'', being known from deposits of Early Silurian (possibly the Llandovery epoch) age and the last members, belonging to the long-lasting and widespread genus ''Adelophthalmus'', going extinct in the Cisuralian, Early Permian, the Adelophthalmidae is the longest lasting single family of eurypterids. The survival of the group, and of swimming eurypterids (the suborder Eurypterina) beyond the Late Devonian is entirely due to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterygotidae
Pterygotidae (the name deriving from the type genus ''Pterygotus'', meaning "winged one") is a family of eurypterids, an extinct group of aquatic arthropods. They were members of the superfamily Pterygotioidea. Pterygotids were the largest known arthropods to have ever lived with some members of the family, such as ''Jaekelopterus'' and '' Acutiramus'', exceeding 2 metres (6.6 ft) in length. Their fossilized remains have been recovered in deposits ranging in age from 428 to 372 million years old ( Late Silurian to Late Devonian). One of the most successful groups of eurypterids, the pterygotids were the only eurypterid family to achieve a truly worldwide distribution. Several evolutionary innovations made the pterygotids unique among the eurypterids, with large and flattened telsons (the posteriormost division of the body) likely used as rudders to provide additional agility and enlarged chelicerae (frontal appendages) with claws. These claws were robust and possessed tee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurypterid
Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the Order (biology), order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 Myr, million years ago. The group is likely to have appeared first either during the Early Ordovician or Late Cambrian period. With approximately 250 species, the Eurypterida is the most diverse Paleozoic Chelicerata, chelicerate order. Following their appearance during the Ordovician, eurypterids became major components of marine faunas during the Silurian, from which the majority of eurypterid species have been described. The Silurian genus ''Eurypterus'' accounts for more than 90% of all known eurypterid specimens. Though the group continued to diversify during the subsequent Devonian period, the eurypterids were heavily affected by the Late Devonian extinction event. They declined in numbers and diversity until becoming extinct during the Permian–Tri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slimonidae
Slimonidae (the name deriving from the type genus '' Slimonia'', which is named in honor of Welsh fossil collector and surgeon Robert Slimon) is a family of eurypterids, an extinct group of aquatic arthropods. Slimonids were members of the superfamily Pterygotioidea and the family most closely related to the derived pterygotid eurypterids, which are famous for their cheliceral claws and great size. Many characteristics of the Slimonidae, such as their flattened and expanded telsons (the posteriormost division of their bodies), support a close relationship between the two groups. Slimonids are defined as pterygotioid eurypterids with swimming legs similar to those of the type genus, ''Slimonia'', and the second to fifth pair of appendages being non-spiniferous. The family contains only two genera, the almost completely known ''Slimonia'' and '' Salteropterus'', which is known only from the telson and the metastoma (a large plate part of the abdomen). Both slimonid genera preserv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hughmilleriidae
Hughmilleriidae (the name deriving from the type genus '' Hughmilleria'', which is named in honor of Scottish geologist Hugh Miller) is a family of eurypterids, an extinct group of aquatic arthropods. The hughmilleriids were the most basal members of the superfamily Pterygotioidea, in contrast with the more derived (more "advanced") families Pterygotidae and Slimonidae. Despite their classification as pterygotioids, the hughmilleriids possessed several characteristics shared with other eurypterid groups, such as the lanceolate telson (the most posterior segment of the body). Hughmilleriids are defined as pterygotioid eurypterids with swimming legs similar to those of the type genus, ''Hughmilleria'' (that is, 7th and 8th leg segments narrow and 9th segment very small), and whose second to fifth pair of appendages were spiniferous. Some further diagnostic characters unite the group, such as the slightly enlarged chelicerae (frontal appendages) and the streamlined shape of their b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slimonia Acuminata
''Slimonia'' is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of ''Slimonia'' have been discovered in deposits of Silurian age in South America and Europe. Classified as part of the family Slimonidae alongside the related '' Salteropterus'', the genus contains three valid species, ''S. acuminata'' from Lesmahagow, Scotland, ''S. boliviana'' from Cochabamba, Bolivia and ''S. dubia'' from the Pentland Hills of Scotland and one dubious species, ''S. stylops'', from Herefordshire, England. The generic name is derived from and honors Robert Slimon, a fossil collector and surgeon from Lesmahagow. Out of the four described species of ''Slimonia'', three measured below or up to in length. Only ''S. acuminata'' was larger, with the largest specimens measuring in length. Though this is large for a predatory arthropod, ''Slimonia'' would be exceeded in length by later and more derived (more "advanced") members of the closely related pterygotid family of eurypteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterygotus Anglicus
''Pterygotus'' is a genus of giant predatory eurypterid, a group of extinct aquatic arthropods. Fossils of ''Pterygotus'' have been discovered in deposits ranging in age from Middle Silurian to Late Devonian, and have been referred to several different species. Fossils have been recovered from four continents; Australia, Europe, North America and South America, which indicates that ''Pterygotus'' might have had a nearly cosmopolitan (worldwide) distribution. The type species, ''P. anglicus'', was described by Swiss naturalist Louis Agassiz in 1839, who gave it the name ''Pterygotus'', meaning "winged one". Agassiz mistakenly believed the remains were of a giant fish; he would only realize the mistake five years later in 1844. ''Pterygotus'' was among the largest eurypterids. Isolated fossil remains of a large chelicera (frontal appendage) suggests that the largest known species, ''P. grandidentatus'', reached a body length of . Several other species, notably ''P. impacatus'' at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterygotus
''Pterygotus'' is a genus of giant predatory eurypterid, a group of extinct aquatic arthropods. Fossils of ''Pterygotus'' have been discovered in deposits ranging in age from Middle Silurian to Late Devonian, and have been referred to several different species. Fossils have been recovered from four continents; Australia, Europe, North America and South America, which indicates that ''Pterygotus'' might have had a nearly cosmopolitan (worldwide) distribution. The type species, ''P. anglicus'', was described by Swiss naturalist Louis Agassiz in 1839, who gave it the name ''Pterygotus'', meaning "winged one". Agassiz mistakenly believed the remains were of a giant fish; he would only realize the mistake five years later in 1844. ''Pterygotus'' was among the largest eurypterids. Isolated fossil remains of a large chelicera (frontal appendage) suggests that the largest known species, ''P. grandidentatus'', reached a body length of . Several other species, notably ''P. impacatus'' at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diploperculata
Diploperculata is an infraorder of eurypterids, an extinct group of aquatic arthropods commonly known as "sea scorpions". The name, derived from Greek διπλόω ("double") and ''operculum'', refers to the distinguishing feature that unites the superfamilies included in the group, that the genital operculum is made up of two fused segments. The group contains the three eurypterine superfamilies Carcinosomatoidea, Adelophthalmoidea and Pterygotioidea alongside the as of yet undescribed " waeringopteroid" clade. The diploperculate eurypterine clade had prior to its description been noted as a monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ... group of derived eurypterines that form a sister-taxon to the superfamily Eurypteroidea. See also * List of eurypterid gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmopolitan Distribution
In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The extreme opposite of a cosmopolitan species is an endemic one, being found only in a single geographical location. Qualification The caveat “in appropriate habitat” is used to qualify the term "cosmopolitan distribution", excluding in most instances polar regions, extreme altitudes, oceans, deserts, or small, isolated islands. For example, the housefly is highly cosmopolitan, yet is neither oceanic nor polar in its distribution. Related terms and concepts The term pandemism also is in use, but not all authors are consistent in the sense in which they use the term; some speak of pandemism mainly in referring to diseases and pandemics, and some as a term intermediate between endemism and cosmopolitanism, in effect regarding pandemism as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercontinent
In geology, a supercontinent is the assembly of most or all of Earth's continent, continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", which leaves room for interpretation and is easier to apply to Precambrian times. To separate supercontinents from other groupings, a limit has been proposed in which a continent must include at least about 75% of the continental crust then in existence in order to qualify as a supercontinent. Supercontinents have assembled and dispersed multiple times in the geologic past (see table). According to modern definitions, a supercontinent does not exist today; the closest in existence to a supercontinent is the current Afro-Eurasian landmass, which covers approx. 57% of Earth's total land area. The last time the continental landmasses were near to one another was 336 to 175 million years ago as the supercontinent, Pangaea. The positions of con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
