A chordate is an animal constituting the phylum Chordata. During some period of their life cycle, chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, an endostyle, a post-anal tail: these five anatomical features define this phylum. Chordates are bilaterally symmetric; the Chordata and Ambulacraria together form the superphylum Deuterostomia. Chordates are divided into three subphyla: Vertebrata. There are extinct taxa such as the Vetulicolia. Hemichordata has been presented as a fourth chordate subphylum, but now is treated as a separate phylum: hemichordates and Echinodermata form the Ambulacraria, the sister phylum of the Chordates. Of the more than 65,000 living species of chordates, about half are bony fish that are members of the superclass Osteichthyes. Chordate fossils have been found from as early as the Cambrian explosion, 541 million years ago. Cladistically, vertebrates - chordates with the notochord replaced by a vertebral column during development - are considered to be a subgroup of the clade Craniata, which consists of chordates with a skull.
The Craniata and Tunicata compose the clade Olfactores. Chordates form a phylum of animals that are defined by having at some stage in their lives all of the following anatomical features: A notochord, a stiff rod of cartilage that extends along the inside of the body. Among the vertebrate sub-group of chordates the notochord develops into the spine, in wholly aquatic species this helps the animal to swim by flexing its tail. A dorsal neural tube. In fish and other vertebrates, this develops into the spinal cord, the main communications trunk of the nervous system. Pharyngeal slits; the pharynx is the part of the throat behind the mouth. In fish, the slits are modified to form gills, but in some other chordates they are part of a filter-feeding system that extracts particles of food from the water in which the animals live. Post-anal tail. A muscular tail that extends backwards behind the anus. An endostyle; this is a groove in the ventral wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus.
It stores iodine, may be a precursor of the vertebrate thyroid gland. There are soft constraints that separate chordates from certain other biological lineages, but are not part of the formal definition: All chordates are deuterostomes; this means. All chordates are based on a bilateral body plan. All chordates are coelomates, have a fluid filled body cavity called a coelom with a complete lining called peritoneum derived from mesoderm; the following schema is from the third edition of Vertebrate Palaeontology. The invertebrate chordate classes are from Fishes of the World. While it is structured so as to reflect evolutionary relationships, it retains the traditional ranks used in Linnaean taxonomy. Phylum Chordata †Vetulicolia? Subphylum Cephalochordata – Class Leptocardii Clade Olfactores Subphylum Tunicata – Class Ascidiacea Class Thaliacea Class Appendicularia Class Sorberacea Subphylum Vertebrata Infraphylum incertae sedis Cyclostomata Superclass'Agnatha' paraphyletic Class Myxini Class Petromyzontida or Hyperoartia Class †Conodonta Class †Myllokunmingiida Class †Pteraspidomorphi Class †Thelodonti Class †Anaspida Class †Cephalaspidomorphi Infraphylum Gnathostomata Class †Placodermi Class Chondrichthyes Class †Acanthodii Superclass Osteichthyes Class Actinopterygii Class Sarcopterygii Superclass Tetrapoda Class Amphibia Class Sauropsida Class Synapsida Craniates, one of the three subdivisions of chordates, all have distinct skulls.
They include the hagfish. Michael J. Benton commented that "craniates are characterized by their heads, just as chordates, or all deuterostomes, are by their tails". Most craniates are vertebrates; these consist of a series of bony or cartilaginous cylindrical vertebrae with neural arches that protect the spinal cord, with projections that link the vertebrae. However hagfish have incomplete braincases and no vertebrae, are therefore not regarded as vertebrates, but as members of the craniates, the group from which vertebrates are thought to have evolved; however the cladistic exclusion of hagfish from the vertebrates is controversial, as they ma
Feliformia is a suborder within the order Carnivora consisting of "cat-like" carnivorans, including cats, mongooses and related taxa. Feliformia stands in contrast to the other suborder of Caniformia; the separation of the Carnivora into the broad groups of feliforms and caniforms is accepted, as is the definition of Feliformia and Caniformia as suborders. The classification of feliforms as part of the Feliformia suborder or under separate groupings continues to evolve. Systematic classifications dealing with only extant taxa include all feliforms into the Feliformia suborder, though variations exist in the definition and grouping of families and genera. Indeed, molecular phylogenies suggest; the extant families as reflected in the taxa chart at right and the discussions in this article reflect the most contemporary and well-supported views. Systematic classifications dealing with both extant and extinct taxa vary more widely; some separate the feliforms as: Feliformia. Others include all feliforms into the Feliformia suborder.
Some studies suggest. The extinct families as reflected in the taxa chart are the least problematic in terms of their relationship with extant feliforms. All extant feliforms share a common attribute: their auditory bullae; this is a key diagnostic in classifying species as feliform versus caniform. In feliforms, the auditory bullae are double-chambered. Caniforms have single-chambered or divided auditory bullae, composed of a single bone; this feature, however, is problematic for the classification of the extinct Nimravidae as feliforms. Nimravid fossils show no trace at all of the entire bulla, it is assumed. The specific characteristics of extant feliform bullae suggest a common ancestor, though one has not been identified in the fossil records. There are other characteristics that differentiate feliforms from caniforms and existed in their stem taxa. But, due to speciation, these do not apply unambiguously to all extant species. Feliforms tend to have shorter rostrums than caniforms, fewer teeth, more specialized carnassials.
Feliforms tend to be more carnivorous and are ambush hunters. Caniforms tend more toward opportunity-based feeders. Many feliforms have retractile or semi-retractile claws and many are arboreal or semi-arboreal. Feliforms tend to be more digitigrade. In contrast, most caniforms have non-retractile claws and tend to be plantigrade. There are seven extant families, twelve subfamilies, 56 genera and 114 species in the Feliformia suborder, they range natively across all continents except Antarctica. Most species are arboreal or semi-arboreal ambush hunters. Target prey varies based on available food sources. An overview of each family is provided here. For detailed taxa and descriptions of the species in each family, follow the links to other articles and external references. Family Eupleridae includes fossa, Malagasy civet and Malagasy mongooses, all of which are restricted to the island of Madagascar; the eight species in the family exhibit significant variations in form. These differences led to the species in this family sharing common names with, being placed in the different families of more similar species on the mainland.
However, phylogenetic analysis of DNA provides strong evidence that all Malagasy carnivorans evolved from a single common ancestor, a herpestid. Phylogenetic analysis supports this view and places all of the Malagasy carnivorans in the family Eupleridae; the differences in form make it difficult to concisely summarise the species in this family. The range in size is as diverse as the range in form, with smaller species at less than 500 g and the largest species at up to 12 kg; some have retractile or semi-retractile claws and others do not. They all tend to have pointed rostra. Diet varies with size and form of the species and, like their mainland counterparts, ranges from small mammals and invertebrates through to crustaceans and molluscs. Family Felidae are the most widespread of the "cat-like" carnivorans. There are 41 extant species, all but a few have retractile claws; this family is represented on all continents except the Antarctic. The species vary in size from the tiny black-footed cat at only 2 kg to the tiger at 300 kg.
Diet ranges from large to small mammals and insects Family Hyaenidae has four extant species and two subspecies. All show features of convergent evolution with canids, including non-retractile claws, long muzzles, adaptations to running for long distances, they are extant in the Middle East and Africa. Hyenas are large, powerful animals, up to 80 kg and represent
Angolan slender mongoose
The Angolan slender mongoose is a mongoose that lives in southern Africa Angola and Namibia. It avoids desert and dense forests; this animal has a long slim body and the males are around 15% bigger than the females. It has 38 teeth. Males do not help in raising the young; the young open their eyes at 3 weeks and leave their mother at around 10 weeks and at 24 weeks get their adult teeth. "Lioncrusher's Domain" listing
The common kusimanse known as the long-nosed kusimanse or cusimanse, is a small, diurnal kusimanse or dwarf mongoose. Of three subfamilies of Herpestidae, the kusimanse is a member of Mungotinae, which are small and social; the common kusimanse has a vaguely weasel-shaped body with dark or reddish brown fur, thick, with a wiry texture down the back, fine and soft on the underside. It has a long snout, short legs, a short stiff tail which tapers to a point, long claws, small ears, dark colored eyes, an elongated nose. Adult size is around 33 cm with a weight of 1 kg; this mongoose is a social animal which lives in a small family group of 10 to 20 or more individuals, with a strict hierarchical structure. The members of the family group communicate through various vocalizations including whistles and growls; the whistles are emitted for the purpose of maintaining contact in the dense rainforest understory while traveling. It tends to restrict most of its activities to the ground, it is territorial, will mark the group's territory with anal scent glands, defend it vehemently against intruders those of a much larger size.
It has a variety of threat displays which include various growls and snorts, as well as physical movements such as lunging, back arching, hair erection. The group is nomadic; as they move from place to place, they find shelter in tree hollows, other animal's burrows, or termite mounds. As they do not occupy permanent den sites, the young are not able to keep up with the group for several weeks and must be carried to different foraging spots. Individuals in the group take turns carrying the young and help to feed them; the common kusimanse is found in the west African countries of Ghana, Ivory Coast, Benin and Sierra Leone, it has been exported to various other countries for the pet trade. It differs from other mongooses in its choice of habitat, forested areas near water, whereas most species of mongoose tend to prefer open grasslands, or semi-arid brush, it can be found from sea level to elevations of 1000 m. Kusimanses are active foragers, excellent diggers, which feed on a wide variety of things.
Their diet is carnivorous, consisting of insects, fresh water crabs, small reptiles, small rodents. They have excellent eyesight and keen sense of smell, they prefer to kill their prey with a single bite to the back of the neck. They will consume various types of fruits and berries in small quantity. Where kusimanses live near human populations, they are "seen as natural pesticides." Due to their hierarchical social structure, only the primary members of a family group are permitted to breed. Subordinate offspring are killed and eaten by the more dominant members of the group. Sexual maturity is reached between nine months of age to a year old. Females go into estrus up to nine times a year. Males terminate copulation without much courting. Gestation is eight weeks, each litter averages 2–4 babies, though they have six mammae. Females are capable of having three litters per year. Babies are born about 13 mm long with their eyes closed, a thick undercoat of fur. After about twelve days, they begin to explore their environment.
At around three weeks the mother weans them, their guard hairs begin to grow in, they forage on their own. They do not grow to adult size until around 6–9 months of age; the life span of the common kusimanse in captivity is 10 years. Due to its ease of training, social nature, the common kusimanse is available in the exotic pet trade and is found in many zoos worldwide, it tends to become quite bonded to its owner, does not interact well with any other kind of household pet. It is energetic, requiring a large amount of space to satiate its natural wandering instinct. Without it, it tends to act out with aggression, its dietary needs can be met with a mix of various things including commercially available crickets, mealworms, or mice, along with a quality cat food. In captivity the risk of obesity is high, care should be taken to assure its diet is varied, that it gets an appropriate amount of exercise, it will try to eat anything it is offered or that it comes across which seems remotely edible, will become aggressive if what it perceives as a food item is taken away.
Captive breeding has been done. The common kusimanse is not listed as threatened or endangered, while no exact numbers of the wild population is known, is not considered to be at risk. Lioncrusher's Domain: Cusimanse Sacramento Zoo: Cusimanse - PDF Animal Diversity Web: Crossarchus obscurus
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. While these definitions may seem adequate, when looked at more they represent problematic species concepts. For example, the boundaries between related species become unclear with hybridisation, in a species complex of hundreds of similar microspecies, in a ring species. Among organisms that reproduce only asexually, the concept of a reproductive species breaks down, each clone is a microspecies. All species are given a two-part name, a "binomial"; the first part of a binomial is the genus.
The second part is called the specific epithet. For example, Boa constrictor is one of four species of the genus Boa. None of these is satisfactory definitions, but scientists and conservationists need a species definition which allows them to work, regardless of the theoretical difficulties. If species were fixed and distinct from one another, there would be no problem, but evolutionary processes cause species to change continually, to grade into one another. Species were seen from the time of Aristotle until the 18th century as fixed kinds that could be arranged in a hierarchy, the great chain of being. In the 19th century, biologists grasped. Charles Darwin's 1859 book The Origin of Species explained how species could arise by natural selection; that understanding was extended in the 20th century through genetics and population ecology. Genetic variability arises from mutations and recombination, while organisms themselves are mobile, leading to geographical isolation and genetic drift with varying selection pressures.
Genes can sometimes be exchanged between species by horizontal gene transfer. Viruses are a special case, driven by a balance of mutation and selection, can be treated as quasispecies. Biologists and taxonomists have made many attempts to define species, beginning from morphology and moving towards genetics. Early taxonomists such as Linnaeus had no option but to describe what they saw: this was formalised as the typological or morphological species concept. Ernst Mayr emphasised reproductive isolation, but this, like other species concepts, is hard or impossible to test. Biologists have tried to refine Mayr's definition with the recognition and cohesion concepts, among others. Many of the concepts are quite similar or overlap, so they are not easy to count: the biologist R. L. Mayden recorded about 24 concepts, the philosopher of science John Wilkins counted 26. Wilkins further grouped the species concepts into seven basic kinds of concepts: agamospecies for asexual organisms biospecies for reproductively isolated sexual organisms ecospecies based on ecological niches evolutionary species based on lineage genetic species based on gene pool morphospecies based on form or phenotype and taxonomic species, a species as determined by a taxonomist.
A typological species is a group of organisms in which individuals conform to certain fixed properties, so that pre-literate people recognise the same taxon as do modern taxonomists. The clusters of variations or phenotypes within specimens would differentiate the species; this method was used as a "classical" method of determining species, such as with Linnaeus early in evolutionary theory. However, different phenotypes are not different species. Species named in this manner are called morphospecies. In the 1970s, Robert R. Sokal, Theodore J. Crovello and Peter Sneath proposed a variation on this, a phenetic species, defined as a set of organisms with a similar phenotype to each other, but a different phenotype from other sets of organisms, it differs from the morphological species concept in including a numerical measure of distance or similarity to cluster entities based on multivariate comparisons of a reasonably large number of phenotypic traits. A mate-recognition species is a group of sexually reproducing organisms that recognize one another as potential mates.
Expanding on this to allow for post-mating isolation, a cohesion species is the most inclusive population of individuals having the potential for phenotypic cohesion through intrinsic cohesion mechanisms. A further development of the recognition concept is provided by the biosemiotic concept of species. In microbiology, genes can move even between distantly related bacteria extending to the whole bacterial domain; as a rule of thumb, microbiologists have assumed that kinds of Bacteria or Archaea with 16S ribosomal RNA gene sequences more similar than 97% to each other need to be checked by DNA-DNA hybridisation to decide if they belong to the same species or not. This concept was narrowed in 2006 to a similarity of 98.7%. DNA-DNA hybri
Herpestes is a genus of the mongoose family. It is the type genus of the family, it contains the following ten species, with a number of subspecies, one extinct species: † Herpestes lemanensis
In zoological nomenclature, a type species is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e. the species that contains the biological type specimen. A similar concept is used for suprageneric groups called a type genus. In botanical nomenclature, these terms have no formal standing under the code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus name is a specimen, the type of a species name; the species name that has that type can be referred to as the type of the genus name. Names of genus and family ranks, the various subdivisions of those ranks, some higher-rank names based on genus names, have such types. In bacteriology, a type species is assigned for each genus; every named genus or subgenus in zoology, whether or not recognized as valid, is theoretically associated with a type species. In practice, there is a backlog of untypified names defined in older publications when it was not required to specify a type.
A type species is both a concept and a practical system, used in the classification and nomenclature of animals. The "type species" represents the reference species and thus "definition" for a particular genus name. Whenever a taxon containing multiple species must be divided into more than one genus, the type species automatically assigns the name of the original taxon to one of the resulting new taxa, the one that includes the type species; the term "type species" is regulated in zoological nomenclature by article 42.3 of the International Code of Zoological Nomenclature, which defines a type species as the name-bearing type of the name of a genus or subgenus. In the Glossary, type species is defined as The nominal species, the name-bearing type of a nominal genus or subgenus; the type species permanently attaches a formal name to a genus by providing just one species within that genus to which the genus name is permanently linked. The species name in turn is fixed, to a type specimen. For example, the type species for the land snail genus Monacha is Helix cartusiana, the name under which the species was first described, known as Monacha cartusiana when placed in the genus Monacha.
That genus is placed within the family Hygromiidae. The type genus for that family is the genus Hygromia; the concept of the type species in zoology was introduced by Pierre André Latreille. The International Code of Zoological Nomenclature states that the original name of the type species should always be cited, it gives an example in Article 67.1. Astacus marinus Fabricius, 1775 was designated as the type species of the genus Homarus, thus giving it the name Homarus marinus. However, the type species of Homarus should always be cited using its original name, i.e. Astacus marinus Fabricius, 1775. Although the International Code of Nomenclature for algae and plants does not contain the same explicit statement, examples make it clear that the original name is used, so that the "type species" of a genus name need not have a name within that genus, thus in Article 10, Ex. 3, the type of the genus name Elodes is quoted as the type of the species name Hypericum aegypticum, not as the type of the species name Elodes aegyptica.
Glossary of scientific naming Genetypes – genetic sequence data from type specimens. Holotype Paratype Principle of Typification Type Type genus