1.
Eocene
–
The Eocene Epoch, lasting from 56 to 33.9 million years ago, is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. As with other periods, the strata that define the start and end of the epoch are well identified. The name Eocene comes from the Ancient Greek ἠώς and καινός, the Eocene epoch is conventionally divided into early, middle, and late subdivisions. The corresponding rocks are referred to as lower, middle, the Ypresian stage constitutes the lower, the Priabonian stage the upper, and the Lutetian and Bartonian stages are united as the middle Eocene. The Eocene Epoch contained a variety of different climate conditions that includes the warmest climate in the Cenozoic Era. During this period of time, little to no ice was present on Earth with a difference in temperature from the equator to the poles. Following the maximum was a descent into an icehouse climate from the Eocene Optimum to the Eocene-Oligocene transition at 34 million years ago. During this decrease ice began to reappear at the poles, greenhouse gases, in particular carbon dioxide and methane, played a significant role during the Eocene in controlling the surface temperature. For the early Eocene there is discussion on how much carbon dioxide was in the atmosphere. This is due to numerous proxies representing different atmospheric carbon dioxide content, for contrast, today the carbon dioxide levels are at 400 ppm or 0. 04%. At about the beginning of the Eocene Epoch the amount of oxygen in the atmosphere more or less doubled. During the early Eocene, methane was another gas that had a drastic effect on the climate. In comparison to carbon dioxide, methane has much effect on temperature as methane is ~34 times more effective per molecule than carbon dioxide on a 100-year scale. Most of the methane released to the atmosphere during this period of time would have been from wetlands, swamps, the atmospheric methane concentration today is 0. 000179% or 1.79 ppmv. Due to the climate and sea level rise associated with the early Eocene, more wetlands, more forests. Comparing the early Eocene production of methane to current levels of atmospheric methane, biogenic production of methane produces carbon dioxide and water vapor along with the methane, as well as yielding infrared radiation
2.
Capybara
–
The capybara is the largest rodent in the world. It is a member of the genus Hydrochoerus, of which the other extant member is the lesser capybara. Close relatives are guinea pigs and rock cavies, and it is distantly related to the agouti, chinchillas. Native to South America, the capybara inhabits savannas and dense forests and it is a highly social species and can be found in groups as large as 100 individuals, but usually lives in groups of 10–20 individuals. The capybara is not a species and is hunted for its meat and hide. Its common name is derived from Tupi kaapiûara, a complex agglutination of kaá + píi + ú + ara, meaning one who eats slender leaves, the scientific name, both hydrochoerus and hydrochaeris, comes from Greek ὕδρω + χοίρος. The capybara and the lesser capybara belong to the subfamily Hydrochoerinae along with the rock cavies, the living capybaras and their extinct relatives were previously classified in their own family Hydrochoeridae. Since 2002, molecular studies have recognized a close relationship between Hydrochoerus and Kerodon supporting placement of both genera in a subfamily of Caviidae. The taxonomy of fossil hydrochoerines is also in a state of flux, in recent years, the diversity of fossil hydrochoerines has been substantially reduced. This is largely due to the recognition that capybara molar teeth show strong variation in shape over the life of an individual, the capybara has a heavy, barrel-shaped body and short head, with reddish-brown fur on the upper part of its body that turns yellowish-brown underneath. Its sweat glands can be found in the surface of the portions of its skin. The animal lacks under hair, and guard hair differs little from over hair. Adult capybaras grow to 106 to 134 cm in length, stand 50 to 62 cm tall at the withers, the top recorded weights are 91 kg for a wild female from Brazil and 73.5 kg for a wild male from Uruguay. Capybaras have slightly webbed feet and vestigial tails and their hind legs are slightly longer than their forelegs, they have three toes on their rear feet and four toes on their front feet. Their muzzles are blunt, with nostrils, and the eyes, females are slightly heavier than males. Its karyotype has 2n =66 and FN =102, capybaras are semiaquatic mammals found throughout almost all countries of South America except Chile. They live in forested areas near bodies of water, such as lakes, rivers, swamps, ponds. Capybara have flourished in cattle ranches and they roam in home ranges averaging 10 hectares in high-density populations
3.
Taxonomy (biology)
–
Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
4.
Animal
–
Animals are multicellular, eukaryotic organisms of the kingdom Animalia. The animal kingdom emerged as a clade within Apoikozoa as the group to the choanoflagellates. Animals are motile, meaning they can move spontaneously and independently at some point in their lives and their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs, they must ingest other organisms or their products for sustenance, most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago. Animals can be divided broadly into vertebrates and invertebrates, vertebrates have a backbone or spine, and amount to less than five percent of all described animal species. They include fish, amphibians, reptiles, birds and mammals, the remaining animals are the invertebrates, which lack a backbone. These include molluscs, arthropods, annelids, nematodes, flatworms, cnidarians, ctenophores, the study of animals is called zoology. The word animal comes from the Latin animalis, meaning having breath, the biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects, and humans. Aristotle divided the world between animals and plants, and this was followed by Carl Linnaeus, in the first hierarchical classification. In Linnaeuss original scheme, the animals were one of three kingdoms, divided into the classes of Vermes, Insecta, Pisces, Amphibia, Aves, and Mammalia. Since then the last four have all been subsumed into a single phylum, in 1874, Ernst Haeckel divided the animal kingdom into two subkingdoms, Metazoa and Protozoa. The protozoa were later moved to the kingdom Protista, leaving only the metazoa, thus Metazoa is now considered a synonym of Animalia. Animals have several characteristics that set apart from other living things. Animals are eukaryotic and multicellular, which separates them from bacteria and they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae. They are also distinguished from plants, algae, and fungi by lacking cell walls. All animals are motile, if only at life stages. In most animals, embryos pass through a stage, which is a characteristic exclusive to animals. With a few exceptions, most notably the sponges and Placozoa and these include muscles, which are able to contract and control locomotion, and nerve tissues, which send and process signals
5.
Chordate
–
Chordates are deuterostomes, as during the embryo development stage the anus forms before the mouth. They are also bilaterally symmetric coelomates, in the case of vertebrate chordates, the notochord is usually replaced by a vertebral column during development, and they may have body plans organized via segmentation. There are also additional extinct taxa, the Vertebrata are sometimes considered as a subgroup of the clade Craniata, consisting of chordates with a skull, the Craniata and Tunicata compose the clade Olfactores. Of the more than 65,000 living species of chordates, the worlds largest and fastest animals, the blue whale and peregrine falcon respectively, are chordates, as are humans. Fossil chordates are known from at least as early as the Cambrian explosion, Hemichordata, which includes the acorn worms, has been presented as a fourth chordate subphylum, but it now is usually treated as a separate phylum. The Hemichordata, along with the Echinodermata, form the Ambulacraria, the Chordata and Ambulacraria form the superphylum Deuterostomia, composed of the deuterostomes. Attempts to work out the relationships of the chordates have produced several hypotheses. All of the earliest chordate fossils have found in the Early Cambrian Chengjiang fauna. Because the fossil record of early chordates is poor, only molecular phylogenetics offers a prospect of dating their emergence. However, the use of molecular phylogenetics for dating evolutionary transitions is controversial and it has also proved difficult to produce a detailed classification within the living chordates. Attempts to produce family trees shows that many of the traditional classes are paraphyletic. While this has been known since the 19th century, an insistence on only monophyletic taxa has resulted in vertebrate classification being in a state of flux. Although the name Chordata is attributed to William Bateson, it was already in prevalent use by 1880, ernst Haeckel described a taxon comprising tunicates, cephalochordates, and vertebrates in 1866. Though he used the German vernacular form, it is allowed under the ICZN code because of its subsequent latinization, among the vertebrate sub-group of chordates the notochord develops into the spine, and in wholly aquatic species this helps the animal to swim by flexing its tail. In fish and other vertebrates, this develops into the spinal cord, the pharynx is the part of the throat immediately behind the mouth. In fish, the slits are modified to form gills, a muscular tail that extends backwards behind the anus. This is a groove in the wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus and it also stores iodine, and may be a precursor of the vertebrate thyroid gland
6.
Mammal
–
Mammals are any vertebrates within the class Mammalia, a clade of endothermic amniotes distinguished from reptiles by the possession of a neocortex, hair, three middle ear bones and mammary glands. All female mammals nurse their young with milk, secreted from the mammary glands, Mammals include the largest animals on the planet, the great whales. The basic body type is a quadruped, but some mammals are adapted for life at sea, in the air, in trees. The largest group of mammals, the placentals, have a placenta, Mammals range in size from the 30–40 mm bumblebee bat to the 30-meter blue whale. With the exception of the five species of monotreme, all modern mammals give birth to live young, most mammals, including the six most species-rich orders, belong to the placental group. The largest orders are the rodents, bats and Soricomorpha, the next three biggest orders, depending on the biological classification scheme used, are the Primates, the Cetartiodactyla, and the Carnivora. Living mammals are divided into the Yinotheria and Theriiformes There are around 5450 species of mammal, in some classifications, extant mammals are divided into two subclasses, the Prototheria, that is, the order Monotremata, and the Theria, or the infraclasses Metatheria and Eutheria. The marsupials constitute the group of the Metatheria, and include all living metatherians as well as many extinct ones. Much of the changes reflect the advances of cladistic analysis and molecular genetics, findings from molecular genetics, for example, have prompted adopting new groups, such as the Afrotheria, and abandoning traditional groups, such as the Insectivora. The mammals represent the only living Synapsida, which together with the Sauropsida form the Amniota clade, the early synapsid mammalian ancestors were sphenacodont pelycosaurs, a group that produced the non-mammalian Dimetrodon. At the end of the Carboniferous period, this group diverged from the line that led to todays reptiles. Some mammals are intelligent, with some possessing large brains, self-awareness, Mammals can communicate and vocalize in several different ways, including the production of ultrasound, scent-marking, alarm signals, singing, and echolocation. Mammals can organize themselves into fission-fusion societies, harems, and hierarchies, most mammals are polygynous, but some can be monogamous or polyandrous. They provided, and continue to provide, power for transport and agriculture, as well as commodities such as meat, dairy products, wool. Mammals are hunted or raced for sport, and are used as model organisms in science, Mammals have been depicted in art since Palaeolithic times, and appear in literature, film, mythology, and religion. Defaunation of mammals is primarily driven by anthropogenic factors, such as poaching and habitat destruction, Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is accepted, McKenna & Bell and Wilson & Reader provide useful recent compendiums. Though field work gradually made Simpsons classification outdated, it remains the closest thing to a classification of mammals
7.
Rodent
–
Rodents 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 species are rodents, they are found in vast numbers on all continents except Antarctica. They are the most diversified mammalian order and live in a variety of terrestrial habitats, Species can be arboreal, fossorial, or semiaquatic. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, hamsters, and capybaras. Other animals such as rabbits, hares, and pikas, whose incisors also grow continually, were included with them, but are now considered to be in a separate order. Nonetheless, Rodentia and Lagomorpha are sister groups, sharing a most recent common ancestor, most rodents are small animals with robust bodies, short limbs, and long tails. They use their incisors to gnaw food, excavate burrows. Most eat seeds or other plant material, but some have more varied diets and they tend to be social animals and many species live in societies with complex ways of communicating with each other. Mating among rodents can vary from monogamy, to polygyny, to promiscuity, many have litters of underdeveloped, altricial young, while others are precocial at birth. The rodent fossil record back to the Paleocene on the supercontinent of Laurasia. Rodents greatly diversified in the Eocene, as spread across continents. Rodents reached both South America and Madagascar from Africa, and were the only placental mammals to reach. Rodents have been used as food, for clothing, as pets, some species, in particular the brown rat, the black rat, and the house mouse, are serious pests, eating and spoiling food stored by humans, and spreading diseases. The distinguishing feature of the rodents is their pairs of continuously growing and these incisors have thick layers of enamel on the front and little enamel on the back. Because they do not stop growing, the animal must continue to wear them down so that they do not reach and pierce the skull. As the incisors grind against each other, the softer dentine on the rear of the teeth wears away, most species have up to 22 teeth with no canines or anterior premolars. A gap, or diastema, occurs between the incisors and the teeth in most species. This allows rodents to suck in their cheeks or lips to shield their mouth and throat from wood shavings and other inedible material, chinchillas and guinea pigs have a high-fiber diet, their molars have no roots and grow continuously like their incisors
8.
Johann Friedrich von Brandt
–
Johann Friedrich von Brandt was a German naturalist, who worked mostly in Russia. Brandt was born in Jüterbog and educated at a gymnasium in Wittenberg, in 1831 he emigrated to Russia, and soon was appointed director of the Zoological Museum of the St Petersburg Academy of Sciences. Brandt encouraged the collection of animals, many of which were not represented in the museum. Many specimens began to arrive from the expeditions of Severtzov, Przhevalsky, Middendorff, Schrenck and he described several birds collected by Russian explorers off the Pacific Coast of North America, including Brandts cormorant, red-legged kittiwake and spectacled eider. As a paleontologist, Brandt ranks among the best and he was also an entomologist, specialising in Coleoptera and Diplopoda. He died in Merreküll, Governorate of Estonia and he is also commemorated in Brandts bat, Brandts hedgehog, three other species of mammals, and the lizard Iranolacerta brandtii. In addition, Johann Friedrich von Brandt concerned the continuation of the work Getreue Darstellung und Beschreibung der in der Arzneykunde gebräuchlichen Gewächse of Friedrich Gottlob Hayne, Getreue Darstellung und Beschreibung der in der Arzneykunde gebräuchlichen Gewächse wie auch solcher, welche mit ihnen verwechselt werden können. Band 2, Kryptogamen Hirschwald, Berlin 1838 Digital edition by the University, ztg.37743 Anonym 1879, Naturaliste Canad. Anz.2480 Medvedev, G. S.2000 Trudy Russk, ratzeburg, J. T. C.1874 Forstwissenschaftliches Schriftsteller-Lexikon. Berlin, Nicolaische Buchhandlung, X+1-516 72-76 Strauch, A.1889 Das zoologische Museum der Kaiserlichen Akademie der Wissenschaften zu St. Petersburg in seinem fünfzigjährigen Bestehen. Works by Johann Friedrich von Brandt at Project Gutenberg Works by or about Johann Friedrich von Brandt at Internet Archive Brandt J. F. scanned books, Brandt, Johann Friedrich in Complete Dictionary of Scientific Biography
9.
Dipodoidea
–
The Dipodidae, or dipodids, are a family of rodents found across the Northern Hemisphere, the sole family in the superfamily Dipodoidea. This family includes over 50 species among the 16 genera and they include the jerboas, jumping mice, and birch mice. Different species are found in grassland, deserts, and forests and they are all capable of saltation, a feature that is most highly evolved in the desert-dwelling jerboas. Dipodids are small to medium-sized rodents, ranging from 4 to 26 cm in body length and they are all adapted for jumping, although to varying degrees. The jerboas have very long legs which, in most species. They move either by jumping, or by walking on their hind legs, the jumping mice have long feet, but lack the extreme adaptations of the jerboas, so that they move by crawling or making short hops, rather than long leaps. Both jerboas and jumping mice have long tails to aid their balance, birch mice have shorter tails and feet, but they, too, move by jumping. Most dipodids are omnivorous, with a diet consisting of seeds, some species of jerboa, however, such as Allactaga sibirica, are almost entirely insectivorous. Like other rodents, they have gnawing incisors separated from the cheek teeth by a gap. The dental formula for dipodids is, Jerboas and birch mice make their nests in burrows, in contrast, while jumping mice sometimes co-opt the burrows of other species, they do not dig their own, and generally nest in thick vegetation. Most species hibernate for at least half the year, surviving on fat that they build up in the prior to going to sleep. Dipodids give birth to litters of two and seven young after a gestation period of between 17 and 42 days. They breed once or twice a year, depending on the species
10.
Zygomasseteric system
–
The zygomasseteric system in rodents is the anatomical arrangement of the masseter muscle of the jaw and the zygomatic arch of the skull. The anteroposterior or propalinal motion of the rodent jaw is enabled by an extension of the zygomatic arch, the main types are described as protrogomorphous, sciuromorphous, hystricomorphous, and myomorphous. This is the condition, found in the family Aplodontiidae. The rostrum is unmodified and the masseter originates on the ventral zygomatic surface, the Bathyergidae is considered secondarily protrogomorphous since its zygomatic condition clearly derived from a hystricomorphous ancestor. The ventral surface of the zygoma tilts and broadens into a zygomatic plate, the lateral masseter extends forwards onto the rostrum. The superficial masseter extends forwards along the zygoma and this condition is found in most of the family Sciuridae, and also in the Castoridae, the Eomyidae, and the Geomyoidea. The medial masseter is enlarged, and passes through an enlarged infraorbital foramen to originate on the side of the rostrum, the superficial masseter originates on the front edge of the zygoma, and the lateral masseter extends over most of its length. This condition is found throughout the suborders Hystricomorpha and Anomaluromorpha, in the suborder Myomorpha, it is found in the superfamily Dipodoidea and some fossil Muroidea. Hystricomorphy is also found in the African dormouse Graphiurus, which is a member of the suborder Sciuromorpha, a combination of the expanded and tilted zygoma of sciuromorphy and the enlarged foramen of hystricomorphy. This condition is found in the Muroidea and most Gliridae, korth & Emry 1991 suggest that the infraorbital foramen of the extinct sciurid subfamily Cedromurinae may have allowed for the passage of the masseter muscle. If true, this subfamily would represent an example of myomorphy in the rodent suborder Sciuromorpha. Bell, Sean D. Aplodontid, Scuirid, Castorid, Zapodid and Geomyoid rodents of the Rodent Hill locality, Cypress Hills Formation, Southwest Saskatchewan, Master of Science thesis, korth, William W. Emry, Robert J. The skull of Cedromus and a review of the Cedromurinae
. PMID 21993503.
