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Seppo Koponeni
''Seppo'' is an extinct genus of spiders, possibly of the superfamily Palpimanoidea, that lived about 180 million years ago, in the Early Jurassic (Lower Toarcian) of what is now Europe. The sole species ''Seppo koponeni'' is known from a single fossil from Grimmen, Germany. With the scorpion '' Liassoscorpionides'', it is one of the two only known arachnids from the Lower Jurassic of Germany. ''Seppo'' is the first unequivocal Early Jurassic spider, and was recovered from the ''Green Series'' member of the Toarcian Ciechocinek Formation. Description The spider was described from a single female specimen. It is unknown if was an adult. The carapace is unknown, and besides that has preserved bowed converging sides with a curved posterior margin with straight posterior border of the labium, with row of at least 12 peg teeth along the cheliceral furrow, no true teeth, scattered setae on anterior surface, and slender pedipalps. Legs are preserved, the first and second being much ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toarcian
The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian Age began with the Toarcian turnover, the extinction event that sets its fossil faunas apart from the previous Pliensbachian age. It is believed to have ended with a global cooling event known as the Comptum Cooling Event, although whether it represented a worldwide event is controversial. Stratigraphic definitions The Toarcian takes its name from the city of Thouars, just south of Saumur in the Loire Valley of France. The stage was introduced by French palaeontologist Alcide d'Orbigny in 1842, after examining rock strata of this age in a quarry near Thouars. In Europe this period is represented by the upper part of the Lias. The base of the Toarcian is defined as the place in the stratigraphic record where the ammonite genus '' Eoda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pomerania
Pomerania ( pl, Pomorze; german: Pommern; Kashubian: ''Pòmòrskô''; sv, Pommern) is a historical region on the southern shore of the Baltic Sea in Central Europe, split between Poland and Germany. The western part of Pomerania belongs to the German states of Mecklenburg-Western Pomerania and Brandenburg, while the eastern part belongs to the West Pomeranian, Pomeranian and Kuyavian-Pomeranian voivodeships of Poland. Its historical border in the west is the Mecklenburg-Western Pomeranian border '' Urstromtal'' which now constitutes the border between the Mecklenburgian and Pomeranian part of Mecklenburg-Western Pomerania, while it is bounded by the Vistula River in the east. The easternmost part of Pomerania is alternatively known as Pomerelia, consisting of four sub-regions: Kashubia inhabited by ethnic Kashubians, Kociewie, Tuchola Forest and Chełmno Land. Pomerania has a relatively low population density, with its largest cities being Gdańsk and Szczecin. Ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austrochilidae
Austrochilidae is a small spider family with nine species in two genera. ''Austrochilus'' and ''Thaida'' are endemic to the Andean forest of central and southern Chile and adjacent Argentina. Taxonomy , two genera are placed in the family Austrochilidae: ''Austrochilus'' and ''Thaida'', found in Chile and Argentina. The taxonomic placement of these genera has varied. In 1968, Lehtinen synonymized ''Austrochilus'' and ''Thaida'' under the latter name, placing the genus in a family he called "Thaididae". However, the family name "Thaididae" is preoccupied, being first used for a family of gastropods in 1887. A single family was accepted by Forster ''et al''. in 1987, under the name "Austrochilidae". Molecular phylogenetic studies agree in placing the two genera as basal members of the Araneomorphae, although the precise details and the family placement are not yet agreed. Phylogeny One hypothesis for the phylogeny of the genera placed in the family is shown below (Austrochilidae g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filistatidae
Crevice weaver spiders (Filistatidae) comprise cribellate spiders with features that have been regarded as " primitive" for araneomorph spiders. They are weavers of funnel or tube webs. The family contains 18 genera and more than 120 described species worldwide. One of the most abundant members of this family in the Americas is the southern house spider (''Kukulcania hibernalis''). Named after the fierce Meso-American god Kukulkan, the females are large (up to nearly 20 mm) dark-colored spiders and males are light brown, smaller (about 10 mm), but more long-legged and with palps that are held together in front of their carapaces like the horn of a unicorn. The males also have a darker streak on the center of the dorsal carapace that causes them to be often mistaken for brown recluse spiders. The tiny members of the genus ''Filistatinella'' are like miniature versions of ''Kukulcania''. The nominate genus ''Filistata'' is Afro-Eurasian in distribution. In many older boo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synspermiata
Synspermiata is a clade of araneomorph spiders, comprising most of the former " haplogynes". They are united by having simpler genitalia than other araneomorph spiders, lacking a cribellum, and sharing an evolutionary history of synspermia – a particular way in which spermatozoa are grouped together when transferred to the female. Synspermia Spermatozoa are produced in a multi-step process. A primary spermatocyte with the full diploid number of chromosomes divides to form two secondary spermatocytes which are haploid, i.e. each has half the diploid number of chromosomes. Each secondary spermatocyte then divides to produce two spermatids which undergo further development to form spermatozoa. In synspermia, two or more spermatids from the same spermatocyte fuse together and are enclosed in an envelope, forming a "capsule". This contrasts with cleistospermia, where the capsules enclose individual spermatozoa. After transfer to the female in either form, decapsulation and activation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entelegynae
The Entelegynae or entelegynes are a subgroup of araneomorph spiders, the largest of the two main groups into which the araneomorphs were traditionally divided. Females have a genital plate ( epigynum) and a "flow through" fertilization system; males have complex palpal bulbs. Molecular phylogenetic studies have supported the monophyly of Entelegynae (whereas the other traditional subgroup, the Haplogynae, has been shown not to be monophyletic). The clade contains both cribellate and ecribellate spiders. Characterization The Entelegynae are characterized primarily by the nature of the female genital system. The ancestral ( plesiomorphic) system is found in non-entelegyne spiders, where there is a single external genital opening in the female's abdomen. One or more males inject sperm from their palpal bulbs via this opening; the sperm is usually stored in special spermathecae (absent in some spiders, e.g. ''Pholcus''). When eggs are released from the ovaries, sperm is also releas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mimetidae
Pirate spiders, members of the family Mimetidae, are araneomorph spiders which typically feed on other spiders. The family Mimetidae contains roughly 200 species divided among 12 genera, of which '' Mimetus'' and ''Ero'' are the most common. Mimetids are usually yellow and brown and are usually long. Mimetids can be recognized by the rows of spine-like hairs on their long front legs; the rows consist of a long spine, followed by a series of progressively shorter ones. Mimetidae usually hunt by picking at the strands on their prey's web to simulate the movements of either a trapped insect or a potential mate. When their prey comes to investigate, they are instead captured and eaten. Some mimetids have been observed to feed on insects as well. The spider-feeding habit presents problems in mating, and little is known about how the males court females to avoid being eaten. However, some male mimetids in the genus ''Gelanor'', found in South America, have enormously long appendag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arachnologist
Arachnology is the scientific study of arachnids, which comprise spiders and related invertebrates such as scorpions, pseudoscorpions, and harvestmen. Those who study spiders and other arachnids are arachnologists. More narrowly, the study of spiders alone ( order Araneae) is known as araneology. The word "arachnology" derives from Greek , ''arachnē'', "spider"; and , ''-logia'', "the study of a particular subject". Arachnology as a science Arachnologists are primarily responsible for classifying arachnids and studying aspects of their biology. In the popular imagination, they are sometimes referred to as spider experts. Disciplines within arachnology include naming species and determining their evolutionary relationships to one another (taxonomy and systematics), studying how they interact with other members of their species and/or their environment (behavioural ecology), or how they are distributed in different regions and habitats (faunistics). Other arachnologists perform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berlin
Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constituent states, Berlin is surrounded by the State of Brandenburg and contiguous with Potsdam, Brandenburg's capital. Berlin's urban area, which has a population of around 4.5 million, is the second most populous urban area in Germany after the Ruhr. The Berlin-Brandenburg capital region has around 6.2 million inhabitants and is Germany's third-largest metropolitan region after the Rhine-Ruhr and Rhine-Main regions. Berlin straddles the banks of the Spree, which flows into the Havel (a tributary of the Elbe) in the western borough of Spandau. Among the city's main topographical features are the many lakes in the western and southeastern boroughs formed by the Spree, Havel and Dahme, the largest of which is Lake Müggelsee. Due to its l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Museum Für Naturkunde
The Natural History Museum (german: Museum für Naturkunde) is a natural history museum located in Berlin, Germany. It exhibits a vast range of specimens from various segments of natural history and in such domain it is one of three major museums in Germany alongside ''Naturmuseum Senckenberg'' in Frankfurt and ''Museum Koenig'' in Bonn. The museum houses more than 30 million zoological, paleontological, and mineralogical specimens, including more than ten thousand type specimens. It is famous for two exhibits: the largest mounted dinosaur in the world (a ''Giraffatitan'' skeleton), and a well-preserved specimen of the earliest known bird, ''Archaeopteryx''. The museum's mineral collections date back to the Prussian Academy of Sciences of 1700. Important historic zoological specimens include those recovered by the German deep-sea Valdiva expedition (1898–99), the German Southpolar Expedition (1901–03), and the German Sunda Expedition (1929–31). Expeditions to fossil beds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spine (zoology)
In a zoological context, spines are hard, needle-like anatomical structures found in both vertebrate and invertebrate species. The spines of most spiny mammals are modified hairs, with a spongy center covered in a thick, hard layer of keratin and a sharp, sometimes barbed tip. Occurrence Mammals Spines in mammals include the prickles of hedgehogs and among rodents, the quills of both New World and Old World porcupines as well as the prickly fur of spiny mice, spiny pocket mice and spiny rats. They are also found on afrotherian tenrecs, marsupial spiny bandicoots and on echidnas, of the monotremes. An ancient synapsid, '' Dimetrodon'', had extremely long spines on its backbone that were joined together with a web of skin that formed a sail-like structure. Many mammalian species, like cats and fossas, also have penile spines. The Mesozoic eutriconodont mammal ''Spinolestes'' already displayed spines similar to those of modern spiny mice. Fish Spines are found in the rays o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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