Rikunarita-ORG/Wikinium huggingface dataset:
# Brown rat

| Brown rat Temporal range: Early Holocene - Recent |
| --- |
|  |
| A wild rat in England |
| Conservation status |
|  Least Concern  (IUCN 3.1) |
| Scientific classification  |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Muridae |
| Genus: | *Rattus* |
| Species: | R. norvegicus |
| Binomial name |
| Rattus norvegicus (Berkenhout, 1769 |
|  |
| Distribution of the brown rat across the world. |

The **brown rat** is *Rattus norvegicus*. It is also known as the *common rat*, *sewer rat*, *wharf rat*, *Norwegian rat* and *Parisian rat*. It is a large brown or grey rat with a head and body length of up to 28 cm (11 in) long, and a tail slightly shorter than that. It weighs between 140 and 500 gms (5 and 17+3⁄4 oz). This rodent has spread to all continents except Antarctica, and is the dominant rat in Europe and much of North America. With rare exceptions, the brown rat lives wherever humans live, especially in urban areas.

The rat has been wrongly associated with the bubonic plague. However, the plague bacterium, *Yersinia pestis*, is endemic in only a few rodent species and is usually transmitted by rat fleas. Carrier rodents today include ground squirrels and wood rats.
# Invasive species

Kudzu, a Japanese vine, is invasive in the southeast United States. Here it grows in Atlanta, Georgia
An **invasive species** is a species which is not native to the place where it is found. It has moved from its native area, where it grew naturally, into a new area. Often it becomes a nuisance species, because in its new habitat it lacks its old enemies. Normally, as a species evolves, so do the things which eat it or parasitise it. Free of natural restraints, the invading species outcompetes its new neighbours.

Kudzu, for example, is called "The weed which ate the South" because it went out of control in the southern United States. The introduction of starlings to North America is another example.

Natural events sometimes allow species to invade new places, as in the Great American Interchange.

## The sparrow in North America

A male house sparrow
The house sparrow, *Passer domesticus*, native to Europe and Asia, has been introduced to North and South America and Australia.

It was introduced deliberately to the U.S.A. in the late 19th century by Eugene Schieffelin. He wanted to introduce to America all the birds mentioned in the works of Shakespeare. Two of these species were great successes: starlings and house sparrows. He organized a society for the importation of foreign birds, incorporated in Albany.

## Related pages

* Introduced species
# Native (ecology)

A species is called **indigenous** or **native** to a place when that species lives there because of the natural environment, not human change. A species is an **indigen** if it lives in the wild and has not had artificial selection by humans.

If a species is in a place because it was moved by humans, the species is not indigenous to that place. It is an introduced species.

## Related pages

* Endemism
# Skull

A typical reptilian skull: *Spinosaurus*

| *Skull* |
| --- |
| A lateral (side) view of the human skull |
| A human skull, seen from the front |
| Identifiers |
| MeSH | D012886 |
| FMA | 54964 |
| Anatomical terms of bone |

A **skull**, or **cranium**, is a set of bones that make up the head of a vertebrate and keep in place all body parts in the head. It supports the structures of the face and forms a protective cavity for the brain.

As well as protecting the brain, the skull fixes the distance between the eyes and between the ears. This allows stereoscopic vision, and helps the brain judge direction and distance of sounds. In some animals, the skull also has a defensive function (e.g. horned ungulates). The frontal bone is where horns are mounted.

The skull is made of a number of joined (fused) flat bones. In humans, the adult skull is normally made up of 28 bones.

## Structure

Skulls can be classified based on fenestras which are window or opening in a skull. There are 5 types of fenestras which are:

* Antorbital fenestra
* Mandibular fenestra
* Quadratojugal fenestra
* Subsquamosal fenestra
* Temporal fenestra

## Other websites

* Skull Module (California State University Department of Anthology)
* Human skull base Archived 2017-05-23 at the Wayback Machine (in German)
# Dentin

Drawing showing dentin
**Dentin** or **dentine** is calcified tissue that makes up the second layer of teeth. In the crown (top) of a tooth, dentin is found between enamel and pulp. In the root of a tooth, it is found between cementum and pulp. Dentin makes up most of a tooth. Dentin is yellow. The yellowness of dentin shows through in a tooth because enamel is semi-translucent.

## Composition

Dentin is made up of

* 70% hydroxylapatite (a mineral found in teeth and bones)
* 20% organic matter (matter that comes from living things)
* 10% water

## Development

The process of creating dentin is called **dentinogenesis**. It is made by odontoblasts, a special type of cell that activates later during formation of teeth. Unlike enamel, a tooth can keep making more dentin throughout life.

## Types

Dentin is divided into different types based on when it is made.

### Primary dentin

Primary dentin makes up most of the tooth. It is the thick bulk between enamel and pulp. Primary dentin is the type of dentin a tooth starts out with. It can also be called circumpulpal (surrounding the pulp) dentin. Mantle dentin is a separate, harder but thinner layer that separates primary dentin from the tooth crown.

### Secondary dentin

Secondary dentin is made after a tooth has already appeared in the mouth. This type of dentin is made throughout life. Newly made dentin is found placed very close to the pulp. It is found between pulp and primary dentin.

### Tertiary dentin

Unlike secondary dentin, tertiary (third in order) dentin is not made continuously throughout life. Tertiary dentine is only made when the tooth is damaged.

## Related pages

* Dentition
* Dental caries
# Chisel

A chisel.
A **chisel** is a sharp and straight tool often used with a hammer to shape wood or other surfaces. Chisels are used by artists to make statues and figures out of stone, marble, or wood. Construction workers use chisels to change the shape of wood and stone so that they can build with them. Sometimes chisels are used to break things so that they can be moved more easily.
# Diastema

A **diastema** is a large gap between teeth. It is a normal feature in many types of land vertebrates, especially mammals. A good example are carnivores like the cat, which has a gap between its canine teeth and its slicing molar teeth. Horses, too, have a diastema between their incisors (which pull the grass) and their molars (which grind it).

* Dental formula
# Molar

**Molars** are special teeth found in mammals, and also the most complex sort of teeth. They are used for grinding food.

Humans have 12 molars in total, in four groups of three at the back of the mouth. The molar which is the farthest back in each group is called a wisdom tooth. The wisdom teeth are the last teeth to appear, usually at around the age of eighteen. These final molars do not erupt in many people.

All molars and premolars have a structure for grinding food. They have elevated (~pointed) parts called **cusps**. These cusps are characteristics of the species in question, but in general they are found on the molars, and to a lesser extent on premolars.
# Baluchistan pygmy jerboa

| Baluchistan pygmy jerboa |
| --- |
|  |
| Conservation status |
|  Data Deficient  (IUCN 3.1) |
| Scientific classification  |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Dipodidae |
| Subfamily: | Cardiocraniinae |
| Genus: | *Salpingotulus* Pavlinov, 1980 |
| Species: | S. michaelis |
| Binomial name |
| Salpingotulus michaelis (FitzGibbon, 1966) |

The **Baluchistan pygmy jerboa** (*Salpingotulus michaelis*) is a species of rodent in the Dipodidae family. It is the only species in the genus *Salpingotulus*. It is endemic to Pakistan.
# Jaw

*For the movie about a shark, see Jaws (movie).*
The left side of a human lower jaw.
The **jaw** is the part of an animal's body that it uses to grab and chew food. In humans, the jaws are two bones in the mouth, the mandible (lower jaw) and maxilla (upper jaw), that let the teeth move up and down in order to chew. The mandible is joined to the skull.

However, in insects, the jaws may open left and right instead, and they are usually outside the mouth instead of inside it. Sea urchins have five jaws with one tooth each. Some animals, even some vertebrates, do not have jaws.

The jaws of most arthropods, like this bull ant, move side to side.
A body part is called a jaw based on what it does, not what it is made of or how it grows. In different animals, it can be made of different kinds of cells and tissue. In the embryos of different animals, it may come from different original places. Even within arthropods, the group that contains insects and lobsters and trilobites and spiders, the jaws of different animals may grow from different original tissues, even though they look similar in adult animals. A pair of appendages that become jaws in one species may become antennae in a different species or legs in another. Moray eels and some other fish have two sets of jaws. The outer jaws in their faces grow from the same tissues as the jaws of other fish, and the inner jaws, called pharyngeal jaws, can come from the same tissue that becomes gills or muscles in other fish.

This sea lamprey has teeth but no jaws.
Marsupials and monotremes are born before their jaws have grown enough for them to drink their mothers' milk the way other baby mammals do. Scientists from Kings' College London found that opossums and other marsupials use tissue from their inner ear to make a temporary jaw so they can feed and grow. They found that baby echidnas also form a temporary jaw using the bones of their inner ear so they can feed and grow.
# Hippopotamidae

| Hippopotamidae |
| --- |
|  |
| *Hippopotamus amphibius* |
| Scientific classification |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Family: | **Hippopotamidae** Gray, 1821 |

**Hippopotamidae** is a group of even-toed ungulate mammals.
There are two living species of *Hippopotamus*.

A *Hippopotamus*
## Taxonomy

* Family Hippopotamidae
	+ Hippopotamus (*Hippopotamus amphibius*)
	+ Pygmy Hippopotamus (*Hexaprotodon liberiensis* or *Choeropsis liberiensis*)

*Beware Of Hippo's Crossing*: road sign in South Africa.
## Other websites
# Coypu

| Nutria Temporal range:  |
| --- |
|  |
| Conservation status |
|  Least Concern  (IUCN 3.1) |
| Scientific classification  |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Echimyidae |
| Subfamily: | Echimyinae |
| Tribe: | Myocastorini |
| Genus: | *Myocastor* |
| Species: | M. coypus |
| Binomial name |
| Myocastor coypus (Molina, 1782) |
|  |
| The range of the Nutria **Regions**  Extant (resident)  Extant & Introduced (resident)**Countries**  Extant & Introduced (resident)  Extant (resident)  Extant & Introduced |

The **nutria** (/ˈnjuːtriə/) or **coypu** (/ˈkɔɪpuː/) (Myocastor coypus) is an herbivorous, is a large, plant-eating, rodent which lives in wetlands. The nutria first came from South America including Argentina, Bolivia, Brazil, Paraguay, Chile, and Uruguay. Animals were taken to Louisiana in the 1930s to be farmed for their fur. Some of these animals escaped and are now living in the Louisiana coastal wetlands. They have become a pest and have damaged the environment.

## Gallery

* Nutria heart
* Skull from various perspectives
* By the river Ljubljanica
* Feral nutria in Oise river in France
* 10-day-old baby nutria
* Track

* Sandro Bertolino, Aurelio Perrone, and Laura Gola "Effectiveness of coypu control in small Italian wetland areas" *Wildlife Society Bulletin* Vol. 33, No. 2 (June 2005) pp. 714–772.
* Carter, Jacoby and Billy P. Leonard: "A Review of the Literature on the Worldwide Distribution, Spread of, and Efforts to Eradicate the Coypu (Myocastor coypus)" *Wildlife Society Bulletin*, Vol. 30, No. 1 (Spring, 2002), pp. 162–175.
* Carter, J., A.L. Foote, and L.A. Johnson-Randall. 1999. "Modeling the effects of nutria (Myocastor coypus) on wetland loss". *Wetlands* 19(1):209–219
* Lauren E. Nolfo-Clements: *Seasonal variations in habitat availability, habitat selection, and movement patterns of Myocastor coypus on a subtropical freshwater floating marsh.* (Dissertation) Tulane University. New Orleans. 2006. ISBN 0-542-60916-9
* Sheffels, Trevor and Mark Systma. "Report on Nutria Management and Research in the Pacific Northwest" Center for Lakes and Reservoir Environmental Sciences and Resources, Portland State University. December 2007. Available on-line:

## Other websites

* The documentary *Rodents of Unusual Size* tells the story of the introduction of nutria to Louisiana and the creative efforts being used in the attempts to eradicate them.
* Saving the Bay: The History of the Chesapeake Bay Nutria Eradication Project Archived 2022-09-20 at the Wayback Machine – USDA/Animal and Plant Health Inspection Service
* Portland State University - Report on nutrias in the Pacific Northwest of North America.
* Species Profile – Nutria (*Myocastor coypus*), National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for nutria.
# Bank vole

| Bank vole |
| --- |
|  |
| Conservation status |
|  Least Concern  (IUCN 3.1) |
| Scientific classification  |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Cricetidae |
| Subfamily: | Arvicolinae |
| Genus: | *Clethrionomys* |
| Species: | C. glareolus |
| Binomial name |
| Clethrionomys glareolus (Schreber, 1780) |
|  |
| Range of bank vole |
| Synonyms |
| * *Myodes glareolus*
* *Evotomys glareolus*
 |

The **bank vole** (*Myodes glareolus*) is a small, type of vole with red-brown fur with some grey patches, its body is around 100 millimeters (3.9 in) long in length and the tail is around 50 millimeters long. They weigh around 20 to 35 grams, they have blunt noses and have small eyes and ears.

## Where it lives

The Bank vole lives in woodlands, oak woods, farmlands, hedgerows, and grasslands in Europe (except for the north and south) and east, north, and central Asia.

## Behavior

The Bank Vole is active during both, day and night, but they rest a lot to stop themselves from getting tired. They make their nests under logs, in tree holes, or sometimes underground. In the autumn they store food for the winter.

### Feeding

Bank voles are omnivorous, meaning that they eat other animals and plants. They eat insects, snails, grass, seeds, fungi, leaves and fruit, like raspberry and hazelnut. They have also been known to eat the bodies of dead animals.

## Lives

Baby Bank voles are born in nests made of grass, moss and feathers. The nests are built above ground, usually in trees. When the babies are born they have no fur and are blind. They live on their mothers milk for the first few weeks of their life. A mother Bank vole has an average of six babies at a time, and can have five litters in a season. A baby Bank vole born in spring will be old enough to breed by the time fall comes. A Bank vole lives for an average of 18 to 20 months.

## Predators

Some predators of the Bank vole are the Barn owls, the Tawny owls, the fox, the weasel, and the stoat.
# Dipodidae

| Dipodidae Temporal range:  |
| --- |
|  |
| *Jaculus orientalis* |
| Scientific classification  |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Suborder: | Myomorpha |
| Superfamily: | Dipodoidea |
| Family: | Dipodidae Fischer de Waldheim, 1817 |
| Subfamilies |
|
Allactaginae
Cardiocraniinae
Dipodinae
Euchoreutinae
Sicistinae
Zapodinae |

The **Dipodidae** are a family of small to medium-sized rodents living in the northern hemisphere. The family has over 50 species in 16 genera.

They include the jerboas, jumping mice, and birch mice. Different species are found in grassland, deserts, and forests. They are all capable of *saltation*, which is jumping from a bipedal stance. This feature is most highly evolved in the desert-dwelling jerboas. Their movement resembles that of kangaroos more than that of true mice.

Most species are nocturnal, and the eyes and ears are noticeably larger than usual in proportion to the body.
# Kangaroo rat

| Kangaroo rat Temporal range: Late Pliocene - Recent |
| --- |
|  |
| Scientific classification |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Subclass: | Eutheria |
| Order: | Rodentia |
| Family: | Heteromyidae |
| Genus: | Dipodomys Gray, 1841 |

**Kangaroo rats** are small rodents from North and Central America. They got their name because they look like small kangaroos when standing upright. But they are not related to kangaroos, except that they are mammals. The genus of the kangaroo rats is called Dipodomys.

Currently, there are 22 species in that genus. They vary in size from 10cm to 20cm, and they weigh between 35 and 180 grams for adult animals.

Kangaroo rats live in dry climates. They can live in deserts also, like the Thar Desert. This means that they have developed traits from other species that live in such climates, but are not related to them. Some of those species are the jerboas, which can be found in the deserts of Africa and Asia, and the hopping mice of the Australian Outback.

All of those species have highly developed hind legs. They also live in deep burrows that protect them from the worst heat of the day. Water may be difficult to find in such climates. Therefore, they only rarely need to drink water. Instead, they have a very efficient metabolism. Their kidneys are much more efficient than human kidneys. They can also chemically split off water from the food they eat.

Kangaroo mice are found in areas of the United States and Mexico, where there is some grass or vegetation left, but which have a rather dry climate. Scientists call those areas arid and semi-arid. The animals live on seeds, leaves, nuts and other fruit they can find. They also catch insects. They are also known for stockpiling (keeping) some food in their burrows, for bad times.

Usually, the animals have a color that blends in nicely with the sandy surroundings. Most often they are a tone of dark yellow to deep brown.

They are nocturnal which means that they are active during the night.

## Other websites

 Media related to Kangaroo rat at Wikimedia Commons

 Data related to Kangaroo rat at Wikispecies
# Flying squirrel

| Flying squirrel Temporal range: Early Oligocene – Recent |
| --- |
|  |
| Northern flying squirrel (*Glaucomys sabrinus*) |
| Scientific classification  |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Sciuridae |
| Subfamily: | Sciurinae |
| Tribe: | Pteromyini Brandt, 1855 |
| Genera |
| *Aeretes*
*Aeromys*
*Belomys*
*Biswamoyopterus*
*Eoglaucomys*
*Eupetaurus*
*Glaucomys*
*Hylopetes*
*Neopetes*
*Iomys*
*Petaurillus*
*Petaurista*
*Petinomys*
*Pteromys*
*Pteromyscus*
*Trogopterus* |

A flying squirrel gliding
**Flying squirrels** are a tribe of 44 species in the squirrel family Sciuridae. Despite the name, none use powered flight: all are gliders.

They are sociable, noisy rodents that glide from tree to tree, using a flap of loose skin that connects their front and hind legs. They can glide up to 150 feet (46 m), steering with their tail, and landing on tree trunks, gripping it with all four feet.

These squirrels are nocturnal (most active at night). They have a life span of about five years in the wild, and about 13 years in captivity. Flying squirrels live in forests in North America, Europe and Asia.

Flying squirrels eat mostly plants, like seeds, nuts, leaves, maple sap, bulbs, bark, flowers, and roots. Less often, they eat insects, eggs, worms, small birds, and other small animals.

Flying squirrels are hunted by weasels, foxes, hawks, and coyotes.

## Evolution

Before the 21st century, the evolutionary history of the flying squirrel was often debated. This debate was clarified by two recent molecular studies. These studies found that the living flying squirrels originated 18–20 million years ago, are monophyletic, and have a sister relationship with tree squirrels.

There are reasons which may explain why gliding has evolved in mammals:

1. economical locomotion: moving between trees using as little energy as possible.
2. finding food: economical searching.
3. avoiding predators.
4. reducing landing forces as compared to simple jumping.
# Agouti

| Agouti |
| --- |
|  |
| Central American agouti (*Dasyprocta punctata*) in Tulum, Mexico. |
| Scientific classification  |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Dasyproctidae |
| Genus: | *Dasyprocta* Illiger, 1811 |
| Type species |
| *Mus aguti* Linnaeus, 1766 (=*Mus leporinus* Linnaeus, 1758) |
| Species |
|
See text |
|  |
| Dasyproctidae distribution. *Dasyprocta* in red; *Myoprocta* in blue (darker where ranges overlap) |

The **agouti** is any of several rodent species of the genus Dasyprocta. They are native to Mexico, Central America, northern and central South America, and the southern Lesser Antilles. Some species have also been introduced elsewhere in the West Indies.

They are related to guinea pigs and look quite similar, but they are larger and have longer legs. The species vary considerably in colour, being brown, reddish, dull orange, greyish, or blackish, but typically with lighter underparts. Their bodies are covered with coarse hair, which is raised when alarmed. They weigh 2.4–6 kg (5.3–13.2 lb) and are 40.5–76 cm (15.9–29.9 in) in length, with short, hairless tails.

## Other websites

* Sereque: The Cutest Mexican Rodent You’ll Ever Meet. Mexico News Network. Archived 2017-06-06 at the Wayback Machine
* Video, photos and information of Azara's agouti
* "Agouti" . *Encyclopædia Britannica* (11th ed.). 1911.
* "Dasyprocta" . *Encyclopedia Americana*. 1920.
# Whisker

A cat's whiskers
A **whisker** is a long, thick hair around the mouth of some animals, mostly mammals such as cats and mice, that the animal uses to feel its surroundings. Some animals, such as cats, also have whiskers above their eyes and on the backs of their legs. Unlike other hair, whiskers should never be cut or trimmed, as this can confuse the animal.

**Whiskers** can also mean a beard or mustache.
# Cecum

Drawing of colon seen from front
(cecum colored red)
The **cecum** is a part of the large intestine. It helps with fermenting dietary fiber. It comes before the colon and after the ileum in the gastrointestinal system. The appendix is connected to the cecum. The size of the cecum varies in humans and other omnivores but it is large in herbivores and small in most carnivores.