Dendrobates Nubeculosus
The Rockstone poison dart frog (''Dendrobates nubeculosus'') is a poorly known species of dendrobatid frogs endemic to Guyana. As it is known from only one specimen, very little information is currently available on ''D. nubeculosus''. It has been suggested to be one of the most poorly known species in the world. Description ''D. nubeculosus'' is a small to medium-sized poison dart frog; larger than many of its contemporary '' Ranitomeya'' species, but smaller than the other members of the genus ''Dendrobates''. The holotype specimen measures 2.5 centimetres in length, and the species' size range is unknown. It is reasonably certain that, like other members of the genus ''Dendrobates'', ''D. nubeculosus'' females are larger than males, but even this is open to speculation. The holotype is primarily black or dark brown, with irregularly shaped blue splotches on the dorsum, and it is mottled blue and black laterally, with a solid black ventral surface. It is unclear whether, as ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Poison Dart Frog
Poison dart frog (also known as dart-poison frog, poison frog or formerly known as poison arrow frog) is the common name of a group of frogs in the family Dendrobatidae which are native to tropical Central and South America. These species are diurnal and often have brightly colored bodies. This bright coloration is correlated with the toxicity of the species, making them aposematic. Some species of the family Dendrobatidae exhibit extremely bright coloration along with high toxicity, while others have cryptic coloration with minimal to no amount of observed toxicity. The species that have great toxicity derive this feature from their diet of ants, mites and termites. However, other species that exhibit cryptic coloration, and low to no amounts of toxicity, eat a much larger variety of prey. Many species of this family are threatened due to human infrastructure encroaching on their habitats. These amphibians are often called "dart frogs" due to the Native Americans' use of the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ornithologist
Ornithology is a branch of zoology that concerns the "methodological study and consequent knowledge of birds with all that relates to them." Several aspects of ornithology differ from related disciplines, due partly to the high visibility and the aesthetic appeal of birds. It has also been an area with a large contribution made by amateurs in terms of time, resources, and financial support. Studies on birds have helped develop key concepts in biology including evolution, behaviour and ecology such as the definition of species, the process of speciation, instinct, learning, ecological niches, guilds, island biogeography, phylogeography, and conservation. While early ornithology was principally concerned with descriptions and distributions of species, ornithologists today seek answers to very specific questions, often using birds as models to test hypotheses or predictions based on theories. Most modern biological theories apply across life forms, and the number of scientists ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Amphibians Of Guyana
Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arboreal or freshwater aquatic ecosystems. Thus amphibians typically start out as larvae living in water, but some species have developed behavioural adaptations to bypass this. The young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin. They are superficially similar to reptiles like lizards but, along with mammals and birds, reptiles are amniotes and do not require water bodies in which to breed. With their complex reproductive needs and permeable skins, amphibians are often ecological indicators; in recent decades there has been a dramatic de ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Endemic Fauna Of Guyana
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example ''Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to sp ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tropical Rainforest
Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equatorial evergreen rainforest''. True rainforests are typically found between 10 degrees north and south of the equator (see map); they are a sub-set of the tropical forest biome that occurs roughly within the 28-degree latitudes (in the equatorial zone between the Tropic of Cancer and Tropic of Capricorn). Within the World Wildlife Fund's biome classification, tropical rainforests are a type of tropical moist broadleaf forest (or tropical wet forest) that also includes the more extensive seasonal tropical forests. Overview Tropical rainforests are characterized by two words: hot and wet. Mean monthly temperatures exceed during all months of the year. Average annual rainfall is no less than and can exceed although it typically lies betwee ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Lowland
Upland and lowland are conditional descriptions of a plain based on elevation above sea level. In studies of the ecology of freshwater rivers, habitats are classified as upland or lowland. Definitions Upland and lowland are portions of plain that are conditionally categorized by their elevation above the sea level. Lowlands are usually no higher than , while uplands are somewhere around to . On unusual occasions, certain lowlands such as the Caspian Depression lie below sea level. Upland habitats are cold, clear and rocky whose rivers are fast-flowing in mountainous areas; lowland habitats are warm with slow-flowing rivers found in relatively flat lowland areas, with water that is frequently colored by sediment and organic matter. These classifications overlap with the geological definitions of "upland" and "lowland". In geology an "upland" is generally considered to be land that is at a higher elevation than the alluvial plain or stream terrace, which are considered to ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Essequibo River
The Essequibo River (Spanish: ''Río Esequibo'' originally called by Alonso de Ojeda ''Río Dulce'') is the largest river in Guyana, and the largest river between the Orinoco and Amazon. Rising in the Acarai Mountains near the Brazil–Guyana border, the Essequibo flows to the north for through forest and savanna into the Atlantic Ocean. With a total drainage basin of and an average discharge of . Territory near the river is argued over by Venezuela and Guyana. Venezuela considers that the natural border according to the divortium aquarum that delimits the eastern margin of that country with the Cooperative Republic of Guyana is "by law", although due to the territorial dispute between the two countries for the sovereignty of Guayana Esequiba, it is "De facto administered and occupied for the most part by the former English colony of British Guiana, present-day Guyana. Geography The river runs through the Guianan moist forests ecoregion. The average annual rainfall in the c ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Rockstone
Rockstone is a village on the right bank of the Essequibo River in the Upper Demerara-Berbice Region of Guyana, altitude 6 metres (22 feet). Rockstone is approximately 26 km west of Linden and is linked by road. The village demographics are mostly Amerindian, but there are also Afro-Guyanese. The population has dwindled as residents seek employment opportunities elsewhere. The town governance is done by a Community Development Council (CDC) and a Community Council that formed in 2012 (also called a village council). The community council seeks to have the village registered and recognized as an Amerindian village, but that has created some conflict as the CDC and village councils have separate aims and property rules. In 1897, a metre gauge industrial railway was built between Rockstone and Wismar (nowadays called Linden). The Essequibo River was hard to navigate, but the Demerara River The Demerara River is a river in eastern Guyana that rises in the central rainforests of ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Type Locality (biology)
In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen. A taxon is a scientifically named grouping of organisms with other like organisms, a set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution. Type specimen According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the scientific name of every taxon is almos ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Bumblebee Poison Dart Frog
The yellow-banded poison dart frog (''Dendrobates leucomelas''), also known as yellow-headed poison dart frog or bumblebee poison frog, is a poison dart frog from the genus ''Dendrobates'' of the family Dendrobatidae. Distribution and habitat ''Dendrobates leucomelas'' is a common poison dart frog found in the northern part of continent of South America, most notably in Venezuela. It is also found in parts of Guyana, Brazil, and the extreme easternmost part of Colombia. This amphibian is normally found in very humid conditions in tropical rain forests, close to fresh water. It is often found on flat rocks, trees, plants (notably bromeliads), and the leaf litter of the forest floor. During the dry season, specimens are known to congregate in damper places, such as under rocks or fallen tree trunks. The ''D. leucomelas natural habitat is tropical, and not subject to great seasonal temperature variations. Typically, temperature variances are related to elevation and time of day, a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Frog
A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" '' Triadobatrachus'' is known from the Early Triassic of Madagascar, but molecular clock dating suggests their split from other amphibians may extend further back to the Permian, 265 million years ago. Frogs are widely distributed, ranging from the tropics to subarctic regions, but the greatest concentration of species diversity is in tropical rainforest. Frogs account for around 88% of extant amphibian species. They are also one of the five most diverse vertebrate orders. Warty frog species tend to be called toads, but the distinction between frogs and toads is informal, not from taxonomy or evolutionary history. An adult frog has a stout body, protruding eyes, anteriorly-attached tongue, limbs folded underneath, and no tail (the tail of tailed frogs ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Sister Taxon
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and taxon B are sister groups to each other. Taxa A and B, together with any other extant or extinct descendants of their most recent common ancestor (MRCA), form a monophyletic group, the clade AB. Clade AB and taxon C are also sister groups. Taxa A, B, and C, together with all other descendants of their MRCA form the clade ABC. The whole clade ABC is itself a subtree of a larger tree which offers yet more sister group relationships, both among the leaves and among larger, more deeply rooted clades. The tree structure shown connects through its root to the rest of the universal tree of life. In cladistic standards, taxa A, B, and C may represent specimens, species, genera, or any other taxonomic units. If A and B are at the same t ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |