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Oceanic Dispersal
Oceanic dispersal is a type of biological dispersal that occurs when Terrestrial animal, 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 (Year#SI prefix multipliers, Ma), and South America, which was isolated for much of the Cenozoic. Both lan ... [...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 than 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 slig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that 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 Ancient Greek (''olígos'') 'few' and (''kainós'') 'new', and refers to the sparsity of Neontology, extant forms of Mollusca, molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major chang ... [...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'' � ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mabuya
''Mabuya'' is a genus of long-tailed skinks, lizards in the family Scincidae. The genus is restricted to species from various Caribbean islands. Out of 26 recognized species, six species are only found in Caribbean islands. Species in the genus ''Mabuya'' 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 as of 2024 include the genera '' Alinea'', '' Aspronema'', '' Brasiliscincus'', '' Capitellum'', '' Copeoglossum'', '' Maracaiba'', '' Marisora'', and '' Varzea''. Most species in this genus are feared to be possibly extinct due to introduced predators. Species Listed alphabeti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skink
Skinks are a type of lizard belonging to the family (biology), family Scincidae, a family in the Taxonomic rank, 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. Etymology The word ''skink'', which entered the English language around 1580–1590, comes from classical Greek and Latin , names that referred to various specific lizards. 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 Tribolonotus gracilis, red-eyed crocodile skink have a head that is ve ... [...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. 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 brille. 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 lick their own brilles whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy adopted by most biological fields. The common ancestor may be an individual, a population, or a species (extinct or Extant taxon, 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 Taxon, taxa that are not clades; that is, taxa that are not Monophyly, monophyletic. Some of the relationships between organisms that the molecul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachylophus
The genus ''Brachylophus'' consists of four Extant taxon, 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 tropics, tropical regions of the Americas and islands in the Galápagos Islands, Galápagos and Lesser Antilles, Lesser and Greater Antilles. Several of these genera are adapted to Deserts and xeric s ... [...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 skulls. The 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 families within the Hystricognathi are divided into two parvorders, the Phiomorpha and the Caviomorpha. The Caviomorpha are mostly native to South America, with a few species in the Caribbean and North America, while the Phiomorpha occur in the Old World. Behavior Play behavior has been observed in seven hystricognath families. The caviomorphs chase each other, play-wrestle, and gallop. The longer-legged species chase more often than the shorter-legged species. They also rotate their heads and body muscles as a form of p ... [...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 monkey, Platyrrhini (New World monkeys) and Catarrhini, the latter of which consists of the family Cercopithecidae (Old World monkeys in the stricter sense) and the superfamily Hominoidea (apesincluding humans). The simians are sister group to the Tarsiiformes, tarsiers (Tarsiiformes), together forming the Haplorhini, haplorhines. The Evolutionary radiation, 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 Old World monkey, Cercopithecidae and apes (including humans). Taxonomy In earlier classification, New World monkeys, Old World monkeys, apes, and humans – collectively known as s ... [...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 scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it, with more than 150 Nobel Prize-winners being featured since its inception. In print since 1845, it is the oldest continuously published magazine in the United States. ''Scientific American'' is owned by Springer Nature, which is a subsidiary of Holtzbrinck Publishing Group. History ''Scientific American'' was founded by inventor and publisher Rufus Porter (painter), Rufus Porter in 1845 as a four-page weekly newspaper. The first issue of the large-format New York City newspaper was released on August 28, 1845. Throughout its early years, much emphasis was placed on reports of what was going on at the United States Patent and Trademark Office, U.S. Patent Office. It also reported on a broad range of inventions including perpetual motion machines, an 1860 devi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caviomorpha
Caviomorpha is the rodent parvorder that unites all New World hystricognaths. It is supported by both fossil and molecular evidence. The Caviomorpha was for a time considered to be a separate order outside the Rodentia, but is now accepted as a genuine part of the rodents. Caviomorphs include the extinct Heptaxodontidae (giant hutias), the extinct '' Josephoartigasia monesi'' (the largest rodent ever known) and extant families of chinchilla rats, hutias, guinea pigs and the capybara, chinchillas and viscachas, tuco-tucos, agoutis, pacas, pacaranas, spiny rats, New World porcupines, coypu and octodonts (Vassallo and Antenucci, 2015). Origin The first known rodent fossils in South America are represented by the three taxa ''Cachiyacuy contamanensis'', ''C. kummeli'', and ''Canaanimys maquiensis'', as well as teeth from ''Eobranisamys'' sp. (Dasyproctidae) and ''Eospina'' sp., the latter two found also in the Santa Rosa fauna from the late Eocene or early Oligocen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
