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Eoplectreurys
''Eoplectreurys'' is an extinct monotypic genus of spider from the family Plectreuridae, with a sole species, ''Eoplectreurys gertschi''. The fossils of ''Eoplectreurys'' were recovered from the ~164 Ma old Middle Jurassic Daohugou formation tuffs in Inner Mongolia, China. History and classification The type specimens are deposited in the Nanjing Institute of Geology and Palaeontology with the genus being described from a total of seven adult spiders. ''Eoplectreurys'' was first studied and described by Drs Paul Selden and Diying Huang, who published their type description in the journal ''Naturwissenschaften'' in 2010. The genus name is a combination of the Greek word ''eos'', which means "dawn", and ''Plectreurys'' the name of the modern genus which the fossils closely resemble. ''Eoplectreurys'' is considered the oldest described spider genus of the Haplogynae series, predating the described Haplogynae spiders from Cretaceous ambers in Jordan and Lebanon, and is the oldes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plectreuridae
Plectreuridae, also called plectreurid spiders, is a small spider family confined to the Southwestern United States, Mexico, and the Caribbean. Only two living genera are known—the nominate genus ''Plectreurys'' and ''Kibramoa''. In the past, the family was more widespread, with the Jurassic genus ''Eoplectreurys'' known from China, the Eocene '' Palaeoplectreurys baltica'' from Baltic amber and the Miocene ''Plectreurys pittfieldi'' from Dominican amber. These ecribellate, haplogyne spiders build haphazard webs under rocks and dead cacti. Adult males can be found wandering at night. Relatively little is known of their biology. Unlike the sicariids, scytodids, and diguetids, to which they are most closely related, they have eight eyes. In appearance females of ''Plectreurys'' resemble those of the larger species of the cribellate Filistatidae. They differ in their eye arrangement and in having the femurs on the first pair of legs bowed. Genera , the World Spider Catalog acc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daohugou Formation
The Tiaojishan Formation is a geological formation in Hebei and Liaoning, People's Republic of China, dating to the middle- late Jurassic period (Bathonian- Oxfordian stages). It is known for its exceptionally preserved fossils, including those of plants, insects and vertebrates. It is made up mainly of pyroclastic rock interspersed with basic volcanic and sedimentary rocks. Previously, the Tiaojishan Formation was grouped together with the underlying Haifanggou Formation (also known as the Jiulongshan Formation) as a single "Lanqi Formation." The Tiaojishan Formation forms a key part of the Yanliao Biota assemblage, alongside the Haifanggou Formation. Age Using Argon–argon dating, Wang and colleagues in 2005 dated part of the Tiaojishan Formation to about 160 million years ago, the beginning of the Oxfordian stage, the first stage of the Upper Jurassic epoch. In 2006, a study by Liu and colleagues used U-Pb zircon dating to conclude that the Tiaojishan Formation correlate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations containing land animal fossils include the Forest Marble Formation in England, the Kilmaluag Formation in Scotland,British Geological Survey. 2011Stratigraphic framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf: research report RR/11/06 British Geological Survey, Keyworth, Nottingham. the Daohugou Beds in China, the Itat Formation in Russia, and the Isalo III Formation of western Madagascar. Paleogeography During the Middle Jurassic Epoch, Pangaea began to separate into Laurasia and Gondwana, and the Atlantic Ocean formed. Eastern Laurasia was tectonically active as the Cimmerian plate continued to collide with Laurasia's southern coast, completely closing the Paleo-Tethys Ocean. A subd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogynae
The Haplogynae or haplogynes are one of the two main groups into which araneomorph spiders have traditionally been divided, the other being the Entelegynae. Morphological phylogenetic studies suggested that the Haplogynae formed a clade; more recent molecular phylogenetic studies refute this, although many of the ecribellate haplogynes do appear to form a clade, Synspermiata. Unlike the Entelegynae, haplogynes lack hardened (sclerotized) female genitalia (epigynes). Most of the species within this group have six eyes, as opposed to most other spiders. Spiders in the genus ''Tetrablemma'' (Tetrablemmidae) have only four eyes, as do some members of the family Caponiidae; caponiids may even have only two eyes. However, spiders in the family Plectreuridae have the normal eight eyes. Phylogeny The Haplogynae are one of the two major groups into which araneomorph spiders were traditionally divided, the other being the Entelegynae. In 2005, Coddington summarized the relationships ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58See the 2014 version of the ICS geologic time scale million years ago. It is the second and most recent epoch of the Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch. Prior to the 2009 revision of the geologic time scale, which placed the fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ... Epoch. The Oligocene is the third and final epoch of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greater Antilles
The Greater Antilles ( es, Grandes Antillas or Antillas Mayores; french: Grandes Antilles; ht, Gwo Zantiy; jam, Grieta hAntiliiz) is a grouping of the larger islands in the Caribbean Sea, including Cuba, Hispaniola, Puerto Rico, Jamaica, and the Cayman Islands. Six island states share the region of the Greater Antilles, with Haiti and the Dominican Republic sharing the island of Hispaniola. Together with the Lesser Antilles, they make up the Antilles. While most of the Greater Antilles consists of independent countries, Puerto Rico is an unincorporated territory of the United States, while the Cayman Islands are a British Overseas Territory. The largest island by area is Cuba, which extends to the western end of the island group. Puerto Rico lies on the eastern end, and the island of Hispaniola, the largest island by population, is located in the middle. Jamaica lies to the south of Cuba, while the Cayman Islands are located to the west. The state of Florida is the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central America
Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. Central America consists of eight countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and Panama. Within Central America is the Mesoamerican biodiversity hotspot, which extends from northern Guatemala to central Panama. Due to the presence of several active geologic faults and the Central America Volcanic Arc, there is a high amount of seismic activity in the region, such as volcanic eruptions and earthquakes which has resulted in death, injury, and property damage. In the pre-Columbian era, Central America was inhabited by the indigenous peoples of Mesoamerica to the north and west and the Isthmo-Colombian peoples to the south and east. Following the Spanish expedition of Christopher Columbus' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Plate, North American Tectonic Plate, Greenland is included as a part of North America geographically. North America covers an area of about , about 16.5% of Earth's land area and about 4.8% of its total surface. North America is the third-largest continent by area, following Asia and Africa, and the list of continents and continental subregions by population, fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in List of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's population. In Americas (terminology)#Human ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dominican Amber
Dominican amber is amber from the Dominican Republic derived from resin of the extinct tree ''Hymenaea protera''. Dominican amber differentiates itself from Baltic amber by being nearly always transparent, and it has a higher number of fossil inclusions. This has enabled the detailed reconstruction of the ecosystem of a long-vanished tropical forest.George Poinar, Jr. and Roberta Poinar, 1999. ''The Amber Forest: A Reconstruction of a Vanished World'', (Princeton University Press) Age A study in the early 1990s returned a date up to 40 million years old. However, according to Poinar, Dominican amber dates from Oligocene to Miocene, thus about 25 million years old. The oldest, and hardest of this amber comes from the mountain region north of Santiago. The ''La Cumbre'', ''La Toca'', ''Palo Quemado'', ''La Bucara'', and ''Los Cacaos'' mining sites in the ''Cordillera Septentrional'' not far from Santiago. Amber has also been found in the south-eastern Bayaguana/Sabana de la Mar a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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