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Petromyscinae
''Petromyscus'' is a genus of rodent in the family Nesomyidae. It is so distinct from other rodents that it is placed as the only genus in subfamily Petromyscinae. In previous classifications, '' Delanymys brooksi'' has also been placed in the subfamily. They are found in southwestern Africa. These animals have a sharp lower point to their V-shaped infraorbital canal. Their molars are intermediate between the ancestral cricetid style tooth and the dendromurine style tooth. The genus contains the following species: * Barbour's rock mouse (''Petromyscus barbouri'') * Pygmy rock mouse (''Petromyscus collinus'') * Brukkaros pygmy rock mouse (''Petromyscus monticularis'') * Shortridge's rock mouse (''Petromyscus shortridgei'') References *Jansa, S. A., S. M. Goodman, and P. K. Tucker. 1999. Molecular phylogeny and biogeography of the native rodents of Madagascar ( Muridae, Nesomyinae): a test of the single origin hypothesis. Cladistics, 15:253-270. *Jansa, S. A. and M. Weksler. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muroidea
The Muroidea are a large superfamily of rodents, including mice, rats, voles, hamsters, lemmings, gerbils, and many other relatives. Although the Muroidea originated in Eurasia, they occupy a vast variety of habitats on every continent except Antarctica. Some authorities have placed all members of this group into a single family, Muridae, due to difficulties in determining how the subfamilies are related to one another. Many of the families within the Muroidea superfamily have more variations between the families than between the different clades. A possible explanation for the variations in rodents is because of the location of these rodents; these changes could have been due to radiation or the overall environment they migrated to or originated in. The following taxonomy is based on recent well-supported molecular phylogenies. The muroids are classified in six families, 19 subfamilies, around 280 genera, and at least 1,750 species. Taxonomy *Family Platacanthomyidae (spiny ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nesomyidae
The Nesomyidae are a family of African rodents in the large and complex superfamily Muroidea. It includes several subfamilies, all of which are native to either continental Africa or to Madagascar. Included in this family are Malagasy rodents, climbing mice, African rock mice, swamp mice, pouched rats, and the white-tailed rat. Characteristics Nesomyids are small- to medium-sized rodents, with the largest being the size of a rat. Physically, they may resemble mice, rats, voles, or hamsters, depending on the species and subfamily. Their diets vary from fairly strict herbivory to nearly pure insectivory. Their habits are similarly variable, with some species climbing trees, and others burrowing in the ground. They give birth to up to four young after a gestation period around six weeks. Classification Many of these animals were once thought to be related to other groups of muroid rodents, but this African-based clade has been proposed and confirmed on the basis of genetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petromyscus
''Petromyscus'' is a genus of rodent in the family Nesomyidae. It is so distinct from other rodents that it is placed as the only genus in subfamily Petromyscinae. In previous classifications, ''Delanymys brooksi'' has also been placed in the subfamily. They are found in southwestern Africa. These animals have a sharp lower point to their V-shaped infraorbital canal. Their molars are intermediate between the ancestral cricetid style tooth and the dendromurine style tooth. The genus contains the following species: * Barbour's rock mouse (''Petromyscus barbouri'') * Pygmy rock mouse (''Petromyscus collinus'') * Brukkaros pygmy rock mouse (''Petromyscus monticularis'') * Shortridge's rock mouse (''Petromyscus shortridgei'') References *Jansa, S. A., S. M. Goodman, and P. K. Tucker. 1999. Molecular phylogeny and biogeography of the native rodents of Madagascar (Muridae, Nesomyinae): a test of the single origin hypothesis. Cladistics, 15:253-270. *Jansa, S. A. and M. Weksler. Ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delanymys Brooksi
Delany's mouse or Delany's swamp mouse (''Delanymys brooksi'') is a species of rodent in the family Nesomyidae. It is the only species in the genus ''Delanymys'' and the only extant member of subfamily Delanymyinae, which also contains the fossil genus '' Stenodontomys''. It was previously placed in subfamily Petromyscinae, but it is apparently not closely related to ''Petromyscus''. It is found in Democratic Republic of the Congo, Rwanda, and Uganda. Its natural habitats are subtropical or tropical high-altitude shrubland and swamps. It is threatened by habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby .... Classification In 2013, a robust muroid phylogeny found ''Delanymys'' sister to ''Mystromys'' + ''Petromyscus'', reviving the affinity of ''Delanymys'' to petromys ... [...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 Neogene Period in the . The Pliocene follows the Epoch and is followed by the Epoch. Prior to the 2009 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogeny
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical framew ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent Genera
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/richochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Rabbits, hares, and pikas, whose incisors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Saur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogeny
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics. All life on Earth is part of a single phylogenetic tree, indicating common ancestry. In a ''rooted'' phylogenetic tree, each node with descendants represents the inferred most recent common ancestor of those descendants, and the edge lengths in some trees may be interpreted as time estimates. Each node is called a taxonomic unit. Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed. Trees are useful in fields of biology such as bioinformatics, systematics, and phylogenetics. ''Unrooted'' trees illustrate only the relatedness of the leaf nodes and do not require the ancestral root to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nesomyinae
The Malagasy rodents are the sole members of the subfamily Nesomyinae. These animals are the only native rodents of Madagascar, come in many shapes and sizes, and occupy a wide variety of ecological niches. There are nesomyines that resemble gerbils, rats, mice, voles, and even rabbits. There are arboreal, terrestrial, and semi-fossorial varieties. These rodents are clearly most closely related to some muroid rodents found on the African mainland. Some molecular phylogeneticists consider this clade of Malagasy and African rodents to represent a distinct family, the Nesomyidae. Other researchers place the Nesomyinae into a large family, Muridae, along with all members of the superfamily Muroidea. It has been reported that the Nesomyinae is not monophyletic, but this has not been supported in other analyses. Additionally, there were problems with this particular study, notably the use of '' Calomyscus'' as an outgroup while more distantly related muroids ( rhyzomyines) were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muridae
The Muridae, or murids, are the largest family of rodents and of mammals, containing approximately 1,383 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia. The name Muridae comes from the Latin ' (genitive '), meaning "mouse", since all true mice belong to the family, with the more typical mice belonging to the genus '' Mus''. Distribution and habitat Murids are found nearly everywhere in the world, though many subfamilies have narrower ranges. Murids are not found in Antarctica or many oceanic islands. Although none of them are native to the Americas, a few species, notably the house mouse and black rat, have been introduced worldwide. Murids occupy a broad range of ecosystems from tropical forests to tundras. Fossorial, arboreal, and semiaquatic murid species occur, though most are terrestrial animals. The extensive list of niches filled by murids helps to explain their relative abundance. Diet and dentiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
