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Oceanic Dispersal
Oceanic dispersal is a type of biological dispersal that occurs when terrestrial organisms transfer from one land mass to another by way of a sea crossing. Island hopping is the crossing of an ocean by a series of shorter journeys between islands, as opposed to a single journey directly to the destination. Often this occurs via large rafts of floating vegetation such as are sometimes seen floating down major rivers in the tropics and washing out to sea, occasionally with animals trapped on them. Dispersal via such a raft is sometimes referred to as a rafting event. Colonization of land masses by plants can also occur via long-distance oceanic dispersal of floating seeds. History Rafting has played an important role in the colonization of isolated land masses by mammals. Prominent examples include Madagascar, which has been isolated for ~120 million years ( Ma), and South America, which was isolated for much of the Cenozoic. Both land masses, for example, appear to have recei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theridion Grallator Colonization Pattern (Hawaiian Volcano Populations)
''Theridion'' is a genus of Theridiidae, tangle-web spiders with a worldwide distribution. Notable species are the Theridion grallator, Hawaiian happy face spider (''T. grallator''), named for the iconic symbol on its abdomen, and ''Theridion nigroannulatum, T. nigroannulatum'', one of few spider species that lives in sociality, social groups, attacking prey en masse to overwhelm them as a team. Identification Spiders in this genus are about as long or longer then they are wide. Their chelicerae have two or less teeth on the front edge and none on the back edge. The front leg is the longest in both genders, but the next longest is the second leg in males and the fourth leg in females. The epigyne can vary, but the pedipalp has a median Glossary_of_spider_terms#apophysis, apophysis and a Cribellum#Ancestral trait, colulus is absent from both genders. In several species, the males have mastidia (projections) on the chelicerae. ''Theridion'' has the anterior eye row sligh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fernando De Noronha
Fernando de Noronha () is an archipelago in the Atlantic Ocean, part of the State of Pernambuco, Brazil, and located off the Brazilian coast. It consists of 21 islands and islets, extending over an area of . Only the eponymous main island is inhabited; it has an area of and a population estimated at 3,101 in 2020. While the archipelago is relatively low-lying, there are parts stretching above in elevation. The islands are administratively unique in Brazil. They form a "state district" ( pt, distrito estadual) that is administered directly by the government of the state of Pernambuco (despite being closer to the state of Rio Grande do Norte). The state district's jurisdiction also includes the very remote Saint Peter and Saint Paul Archipelago, located northeast of Fernando de Noronha. Seventy percent of the islands' area was established in 1988 as a national marine park. In 2001, UNESCO designated it as a World Heritage Site because of its importance as a feeding ground f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trachylepis
''Trachylepis'' is a skink genus in the subfamily Mabuyinae found mainly in Africa. Its members were formerly included in the " wastebin taxon" ''Mabuya'', and for some time in ''Euprepis''. As defined today, ''Trachylepis'' contains the clade of Afro-Malagasy mabuyas. The genus also contains a species from the Brazilian island of Fernando de Noronha, '' T. atlantica'', and may occur in mainland South America with ''Trachylepis tschudii'' and ''Trachylepis maculata'', both poorly known and enigmatic. The ancestors of ''T. atlantica'' are believed to have rafted across the Atlantic from Africa during the last 9 million years. The generic name ''Trachylepis'' literally means "rough-scaled", referring to the fact that most of the species, though superficially smooth-scaled, have three or more slight longitudinal keels on their dorsal scales. Species The following species are recognized as being valid (listed alphabetically by specific name). *''Trachylepis acutilabris'' – w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mabuya
''Mabuya'' is a genus of long-tailed skinks restricted to species from various Caribbean islands. They are primarily carnivorous, though many are omnivorous. The genus is viviparous, having a highly evolved placenta that resembles that of eutherian mammals. Formerly, many Old World species were placed here, as ''Mabuya'' was a kind of "wastebasket taxon". These Old World species are now placed in the genera '' Chioninia'', '' Eutropis'', and ''Trachylepis''. Under the older classification, the New World species were referred to as "American mabuyas", and now include the genera '' Alinea'', '' Aspronema'', '' Brasiliscincus'', '' Capitellum'', '' Maracaiba'', '' Marisora'', '' Varzea'', and '' Copeoglossum''. Most species in this genus are feared to be possibly extinct due to introduced predators. Species Listed alphabetically by specific name. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skink
Skinks are lizards belonging to the family Scincidae, a family in the infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one of the most diverse families of lizards. Skinks are characterized by their smaller legs in comparison to typical lizards and are found in different habitats except arctic and subarctic regions. Description Skinks look like lizards of the family Lacertidae (sometimes called ''true lizards''), but most species of skinks have no pronounced neck and relatively small legs. Several genera (e.g., '' Typhlosaurus'') have no limbs at all. This is not true for all skinks, however, as some species such as the red-eyed crocodile skink have a head that is very distinguished from the body. These lizards also have legs that are relatively small proportional to their body size. Skinks' skulls are covered by substantial bony scales, usually matching up in shape and size, while overlapping. Oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gecko
Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from . Geckos are unique among lizards for their vocalisations, which differ from species to species. Most geckos in the family Gekkonidae use chirping or clicking sounds in their social interactions. Tokay geckos (''Gekko gecko'') are known for their loud mating calls, and some other species are capable of making hissing noises when alarmed or threatened. They are the most species-rich group of lizards, with about 1,500 different species worldwide. All geckos, except species in the family Eublepharidae lack eyelids; instead, the outer surface of the eyeball has a transparent membrane, the cornea. They have a fixed lens within each iris that enlarges in darkness to let in more light. Since they cannot blink, species without eyelids generally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachylophus
The genus ''Brachylophus'' consists of four extant iguanid species native to the islands of Fiji and a giant extinct species from Tonga in the South West Pacific. One of the extant species, ''B. fasciatus'', is also present on Tonga, where it has apparently been introduced by humans. Etymology and taxonomy The name, ''Brachylophus'', is derived from two Greek words: brachys (βραχύς) meaning "short" and lophos (λόφος) meaning "crest" or "plume", denoting the short spiny crests found along the backs of these species. ''Brachylophus'' species are the most geographically isolated iguanas in the world. Their closest extant relatives (the genera '' Amblyrhynchus'', '' Conolophus'', '' Ctenosaura'', '' Cyclura'', '' Iguana'' and '' Sauromalus'') are present in primarily tropical regions of the Americas and islands in the Galápagos and Lesser and Greater Antilles. Several of these genera are adapted to xeric biomes. Phylogenetic evidence supports the ''Brachylophus'' lineag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hystricognathi
The Hystricognathi are an infraorder of rodents, distinguished from other rodents by the bone structure of their skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...s. The masseter, masseter medialis (a jaw muscle) passes partially through a hole below each eye socket (called the infraorbital foramen) and connects to the bone on the opposite side. This, together with their lack of an infraorbital plate and the relative size of the infraorbital foramen, distinguishes hystricognaths from other rodent groups. The 18 family (biology), families within the Hystricognathi are divided into two parvorders, the Phiomorpha and the Caviomorpha. The Caviomorpha are mostly native to List of mammals of South America#Order: Rodentia (rodents), South America, with a few species in the List of r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simian
The simians, anthropoids, or higher primates are an infraorder (Simiiformes ) of primates containing all animals traditionally called monkeys and apes. More precisely, they consist of the parvorders New World monkeys (Platyrrhini) and Catarrhini, the latter of which consists of the superfamilies Cercopithecidae ( Old World monkeys in the stricter sense) and apes ( Hominoidea; including the genus ''Homo''). The simians are sister group to the tarsiers (Tarsiiformes), together forming the haplorhines. The radiation occurred about 60 million years ago (during the Cenozoic era); 40 million years ago, simians colonized South America, giving rise to the New World monkeys. The remaining simians (catarrhines) split about 25 million years ago into Cercopithecidae and apes (including humans). Taxonomy and evolution In earlier classification, New World monkeys, Old World monkeys, apes, and humans – collectively known as simians or anthropoids – were grouped under Anthropoid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific American
''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it is the oldest continuously published magazine in the United States. ''Scientific American'' is owned by Springer Nature, which in turn is a subsidiary of Holtzbrinck Publishing Group. History ''Scientific American'' was founded by inventor and publisher Rufus Porter in 1845 as a four-page weekly newspaper. The first issue of the large format newspaper was released August 28, 1845. Throughout its early years, much emphasis was placed on reports of what was going on at the U.S. Patent Office. It also reported on a broad range of inventions including perpetual motion machines, an 1860 device for buoying vessels by Abraham Lincoln, and the universal joint which now can be found in nearly every automobile manufactured. Current issues inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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