Edward Drinker Cope
Edward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. He was a founder of the Neo-Lamarckism school of thought. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science. Though his father tried to raise Cope as a gentleman farmer, he acquiesced to his son's scientific aspirations. Cope had one child. Cope had little formal scientific training, he eschewed a teaching position for field work, he made regular trips to the American West, prospecting in the 1870s and 1880s as a member of United States Geological Survey teams. A personal feud between Cope and paleontologist Othniel Charles Marsh led to a period of intense fossil-finding competition now known as the Bone Wars. Cope's financial fortunes soured after failed mining ventures in the 1880s, forcing him to sell off much of his fossil collection, he experienced a resurgence in his career toward the end of his life before dying on April 12, 1897.
Though Cope's scientific pursuits nearly bankrupted him, his contributions helped to define the field of American paleontology. He was a prodigious writer, with 1,400 papers published over his lifetime, although his rivals debated the accuracy of his published works, he discovered and named more than 1,000 vertebrate species, including hundreds of fishes and dozens of dinosaurs. His proposal for the origin of mammalian molars is notable among his theoretical contributions. "Cope's rule", the hypothesis that mammalian lineages grow larger over geologic time, while named after him, is "neither explicit nor implicit" in his work. Edward Drinker Cope was born on the eldest son of Alfred and Hanna Cope; the death of his mother when he was three years old seemed to have had little effect on young Edward, as he mentioned in his letters that he had no recollection of her. His stepmother, Rebecca Biddle, filled the maternal role. Alfred, an orthodox member of the Religious Society of Friends or Quakers, operated a lucrative shipping business started by his father, Thomas P. Cope, in 1821.
He was a philanthropist who gave money to the Society of Friends, the Philadelphia Zoological Gardens, the Institute for Colored Youth. Edward was born and raised in a large stone house called "Fairfield", whose location is now within the boundaries of Philadelphia; the 8 acres of pristine and exotic gardens of the house offered a landscape that Edward was able to explore. The Copes began teaching their children to read and write at a young age, took Edward on trips across New England and to museums and gardens. Cope's interest in animals became apparent at a young age. Alfred intended to give his son the same education he himself had received. At age nine, Edward was sent to a day school in Philadelphia and in 1853 at the age of 12, Edward was sent to the Friends' Boarding School at Westtown, near West Chester, Pennsylvania; the school was founded in 1799 with fundraising by members of the Society of Friends, provided much of the Cope family's education. The prestigious school was expensive, costing Alfred $500 in tuition each year, in his first year, Edward studied algebra, scripture, grammar and Latin.
Edward's letters home requesting a larger allowance show he was able to manipulate his father, he was, according to author and Cope biographer Jane Davidson, "a bit of a spoiled brat". His letters suggest he was lonely at the school—it was the first time he had been away from his home for an extended period. Otherwise, Edward's studies progressed much like a typical boy—he had "less than perfect" or "not quite satisfactory" marks for conduct from his teachers, did not work hard on his penmanship lessons, which may have contributed to his illegible handwriting as an adult. Edward returned to Westtown in 1855. Biology began to interest him more that year, he studied natural history texts in his spare time. While at the school, he visited the Academy of Natural Sciences. Edward obtained bad marks due to quarreling and bad conduct, his letters to his father show he chafed at farm work and betrayed flashes of the temper for which he would become well known. After sending Edward back to the farm for summer break in 1854 and 1855, Alfred did not return Edward to school after spring 1856.
Instead, Alfred attempted to turn his son into a gentleman farmer, which he considered a wholesome profession that would yield enough profit to lead a comfortable life, improve the undersized Edward's health. Until 1863, Cope's letters to his father continually expressed his yearning for a more professional scientific career than that of a farmer, which he called "dreadfully boring". While working on farms, Edward continued his education on his own. In 1858, he began working part-time at the Academy of Natural Sciences and cataloguing specimens, published his first series of research results in January 1859. Cope began taking German classes with a former Westtown teacher. Though Alfred resisted his son's pursuit of a science career, he paid for his son's private studies. Instead of working the farm his father bought for him, Edward rented out the land and used the income to further his scientific endeavors. Alfred gave in to Edward's wishes and paid for university cl
The Devonian is a geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian, 419.2 million years ago, to the beginning of the Carboniferous, 358.9 Mya. It is named after Devon, where rocks from this period were first studied; the first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, by the end of the period the first seed-bearing plants appeared. Various terrestrial arthropods became well-established. Fish reached substantial diversity during this time, leading the Devonian to be dubbed the "Age of Fishes." The first ray-finned and lobe-finned bony fish appeared, while the placoderms began dominating every known aquatic environment. The ancestors of all four-limbed vertebrates began adapting to walking on land, as their strong pectoral and pelvic fins evolved into legs.
In the oceans, primitive sharks became more numerous than in the Late Ordovician. The first ammonites, species of molluscs, appeared. Trilobites, the mollusc-like brachiopods and the great coral reefs, were still common; the Late Devonian extinction which started about 375 million years ago affected marine life, killing off all placodermi, all trilobites, save for a few species of the order Proetida. The palaeogeography was dominated by the supercontinent of Gondwana to the south, the continent of Siberia to the north, the early formation of the small continent of Euramerica in between; the period is named after Devon, a county in southwestern England, where a controversial argument in the 1830s over the age and structure of the rocks found distributed throughout the county was resolved by the definition of the Devonian period in the geological timescale. The Great Devonian Controversy was a long period of vigorous argument and counter-argument between the main protagonists of Roderick Murchison with Adam Sedgwick against Henry De la Beche supported by George Bellas Greenough.
Murchison and Sedgwick named the period they proposed as the Devonian System. While the rock beds that define the start and end of the Devonian period are well identified, the exact dates are uncertain. According to the International Commission on Stratigraphy, the Devonian extends from the end of the Silurian 419.2 Mya, to the beginning of the Carboniferous 358.9 Mya. In nineteenth-century texts the Devonian has been called the "Old Red Age", after the red and brown terrestrial deposits known in the United Kingdom as the Old Red Sandstone in which early fossil discoveries were found. Another common term is "Age of the Fishes", referring to the evolution of several major groups of fish that took place during the period. Older literature on the Anglo-Welsh basin divides it into the Downtonian, Dittonian and Farlovian stages, the latter three of which are placed in the Devonian; the Devonian has erroneously been characterised as a "greenhouse age", due to sampling bias: most of the early Devonian-age discoveries came from the strata of western Europe and eastern North America, which at the time straddled the Equator as part of the supercontinent of Euramerica where fossil signatures of widespread reefs indicate tropical climates that were warm and moderately humid but in fact the climate in the Devonian differed during its epochs and between geographic regions.
For example, during the Early Devonian, arid conditions were prevalent through much of the world including Siberia, North America, China, but Africa and South America had a warm temperate climate. In the Late Devonian, by contrast, arid conditions were less prevalent across the world and temperate climates were more common; the Devonian Period is formally broken into Early and Late subdivisions. The rocks corresponding to those epochs are referred to as belonging to the Lower and Upper parts of the Devonian System. Early DevonianThe Early Devonian lasted from 419.2 ± 2.8 to 393.3 ± 2.5 and began with the Lochkovian stage, which lasted until the Pragian. It spanned from 410.8 ± 2.8 to 407.6 ± 2.5, was followed by the Emsian, which lasted until the Middle Devonian began, 393.3± 2.7 million years ago. During this time, the first ammonoids appeared. Ammonoids during this time period differed little from their nautiloid counterparts; these ammonoids belong to the order Agoniatitida, which in epochs evolved to new ammonoid orders, for example Goniatitida and Clymeniida.
This class of cephalopod molluscs would dominate the marine fauna until the beginning of the Mesozoic era. Middle DevonianThe Middle Devonian comprised two subdivisions: first the Eifelian, which gave way to the Givetian 387.7± 2.7 million years ago. During this time the jawless agnathan fishes began to decline in diversity in freshwater and marine environments due to drastic environmental changes and due to the increasing competition and diversity of jawed fishes; the shallow, oxygen-depleted waters of Devonian inland lakes, surrounded by primitive plants, provided the environment necessary for certain early fish to develop such essential characteristics as well developed lungs, the ability to crawl out of the water and onto the land for short periods of time. Late DevonianFinally, the Late Devonian started with the Frasnian, 382.7 ± 2.8 to 372.2 ± 2.5, during which the first forests took shape on land. The first tetrapods appeared in the fossil record in the ensuing Famennian subdivisi
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
North America is a continent within the Northern Hemisphere and all within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, to the southeast by South America and the Caribbean Sea. North America covers an area of about 24,709,000 square kilometers, about 16.5% of the earth's land area and about 4.8% of its total surface. North America is the third largest continent by area, following Asia and Africa, the fourth by population after Asia and Europe. In 2013, its population was estimated at nearly 579 million people in 23 independent states, or about 7.5% of the world's population, if nearby islands are included. North America was reached by its first human populations during the last glacial period, via crossing the Bering land bridge 40,000 to 17,000 years ago; the so-called Paleo-Indian period is taken to have lasted until about 10,000 years ago. The Classic stage spans the 6th to 13th centuries.
The Pre-Columbian era ended in 1492, the transatlantic migrations—the arrival of European settlers during the Age of Discovery and the Early Modern period. Present-day cultural and ethnic patterns reflect interactions between European colonists, indigenous peoples, African slaves and their descendants. Owing to the European colonization of the Americas, most North Americans speak English, Spanish or French, their culture reflects Western traditions; the Americas are accepted as having been named after the Italian explorer Amerigo Vespucci by the German cartographers Martin Waldseemüller and Matthias Ringmann. Vespucci, who explored South America between 1497 and 1502, was the first European to suggest that the Americas were not the East Indies, but a different landmass unknown by Europeans. In 1507, Waldseemüller produced a world map, in which he placed the word "America" on the continent of South America, in the middle of what is today Brazil, he explained the rationale for the name in the accompanying book Cosmographiae Introductio:... ab Americo inventore... quasi Americi terram sive Americam.
For Waldseemüller, no one should object to the naming of the land after its discoverer. He used the Latinized version of Vespucci's name, but in its feminine form "America", following the examples of "Europa", "Asia" and "Africa". Other mapmakers extended the name America to the northern continent, In 1538, Gerard Mercator used America on his map of the world for all the Western Hemisphere; some argue that because the convention is to use the surname for naming discoveries, the derivation from "Amerigo Vespucci" could be put in question. In 1874, Thomas Belt proposed a derivation from the Amerrique mountains of Central America. Marcou corresponded with Augustus Le Plongeon, who wrote: "The name AMERICA or AMERRIQUE in the Mayan language means, a country of perpetually strong wind, or the Land of the Wind, and... the can mean... a spirit that breathes, life itself." The United Nations formally recognizes "North America" as comprising three areas: Northern America, Central America, The Caribbean.
This has been formally defined by the UN Statistics Division. The term North America maintains various definitions in accordance with context. In Canadian English, North America refers to the land mass as a whole consisting of Mexico, the United States, Canada, although it is ambiguous which other countries are included, is defined by context. In the United States of America, usage of the term may refer only to Canada and the US, sometimes includes Greenland and Mexico, as well as offshore islands. In France, Portugal, Romania and the countries of Latin America, the cognates of North America designate a subcontinent of the Americas comprising Canada, the United States, Mexico, Greenland, Saint Pierre et Miquelon, Bermuda. North America has been referred to by other names. Spanish North America was referred to as Northern America, this was the first official name given to Mexico. Geographically the North American continent has many subregions; these include cultural and geographic regions. Economic regions included those formed by trade blocs, such as the North American Trade Agreement bloc and Central American Trade Agreement.
Linguistically and culturally, the continent could be divided into Latin America. Anglo-America includes most of Northern America and Caribbean islands with English-speaking populations; the southern North American continent is composed of two regions. These are the Caribbean; the north of the continent maintains recognized regions as well. In contrast to the common definition of "North America", which encompasses the whole continent, the term "North America" is sometimes used to refer only to Mexico, the United States, Greenland; the term Northern America refers to the northern-most countries and territories of North America: the United States, Bermuda, St. Pierre and Miquelon and Greenland. Although the term does not refer to a unifie
Pangolins or scaly anteaters are mammals of the order Pholidota. The one extant family, has three genera: Manis, which comprises four species living in Asia; these species range in size from 30 to 100 cm. A number of extinct pangolin species are known. Pangolins have protective keratin scales covering their skin, they live depending on the species. Pangolins are nocturnal, their diet consists of ants and termites, which they capture using their long tongues, they tend to be solitary animals, meeting only to mate and produce a litter of one to three offspring, which are raised for about two years. Pangolins are threatened by poaching and heavy deforestation of their natural habitats, are the most trafficked mammals in the world. Of the eight species of pangolin, four are listed as vulnerable, two are listed as endangered, two are listed as critically endangered on the International Union for Conservation of Nature Red List of Threatened Species; the name pangolin comes from the Malay word pengguling, meaning "one who rolls up".
However, the modern name in Standard Malay is tenggiling. The etymologies of the three generic names Manis and Smutsia are sometimes misunderstood. Carl Linnaeus invented the Neo-Latin generic name Manis as a feminine singular form of the Latin masculine plural Manes, the Ancient Roman name for a type of spirit, after the animal's strange appearance. Constantine Rafinesque formed the Neo-Latin generic name Phataginus from the French term phatagin, adopted by Count Buffon after the reported local name phatagin or phatagen used in the East Indies; the British naturalist John Edward Gray named Smutsia for the South African naturalist Johannes Smuts, the first South African to do a treatise on mammals in 1832. The physical appearance of a pangolin is marked by large hardened overlapping plate-like scales, which are soft on newborn pangolins, but harden as the animal matures, they are made of keratin, the same material from which human fingernails and tetrapod claws are made, are structurally and compositionally different from the scales of reptiles.
The pangolin's scaled body is comparable in appearance to a pine cone. It can curl up into a ball when threatened, with its overlapping scales acting as armor, while it protects its face by tucking it under its tail; the scales are sharp. Pangolins can emit a noxious-smelling chemical from glands near the anus, similar to the spray of a skunk, they have short legs, with sharp claws which they use for burrowing into ant and termite mounds, climbing. The tongues of pangolins are long and – like those of the giant anteater and the tube-lipped nectar bat – the root of the tongue is not attached to the hyoid bone, but is in the thorax between the sternum and the trachea. Large pangolins can extend their tongues as much as 40 cm, with a diameter of only 0.5 cm. Most pangolins are nocturnal animals; the long-tailed pangolin is active by day, while other species of pangolins spend most of the daytime sleeping, curled up into a ball. They are considered to be secretive creatures. Arboreal pangolins live in hollow trees, whereas the ground-dwelling species dig tunnels underground, to a depth of 3.5 m.
Some pangolins walk with their front claws bent under the foot pad, although they use the entire foot pad on their rear limbs. Furthermore, some may walk a few steps bipedally. Pangolins are good swimmers. Pangolins are insectivorous. Most of their diet consists of various species of ants and termites and may be supplemented by other insects larvae, they are somewhat particular and tend to consume only one or two species of insects when many species are available to them. A pangolin can consume 140 to 200 g of insects per day. Pangolins are an important regulator of termite populations in their natural habitats. Pangolins have a poor sense of vision, so they rely on smell and hearing. Pangolins lack teeth, therefore they have evolved other physical characteristics to help them eat ants and termites, their skeletal structure is sturdy and they have strong front legs that are useful for tearing into termite mounds. They use their powerful front claws to dig into trees and vegetation to find prey proceed to use their long tongues to probe inside the insect tunnels and to retrieve their prey.
The structure of their tongue and stomach is key to aiding pangolins in obtaining and digesting insects. Their saliva is sticky, causing ants and termites to stick to their long tongues when they are hunting through insect tunnels. Without teeth, pangolins lack the ability to chew; this part of their stomach is called the gizzard, it is covered in keratinous spines. These spines further aid in digestion of the pangolin's prey; some species, such as the tree pangolin, use their strong, prehensile tails to hang from tree branches and
Anteater is a common name for the four extant mammal species of the suborder Vermilingua known for eating ants and termites. The individual species have other names in other languages. Together with the sloths, they are within the order Pilosa; the name "anteater" is colloquially applied to the unrelated aardvark, echidnas and some members of the Oecobiidae. Extant species are the giant anteater Myrmecophaga tridactyla, about 1.8 m long including the tail. The anteaters are more related to the sloths than they are to any other group of mammals, their next closest relations are armadillos. There are four extant species in three genera: Giant anteater Silky anteater Northern and southern tamandua There are several extinct genera as well. Order Pilosa Suborder Folivora Suborder Vermilingua Family Cyclopedidae Genus Cyclopes Silky anteater Genus †Palaeomyrmidon Family Myrmecophagidae Genus Myrmecophaga Giant anteater Genus †Neotamandua Genus Tamandua Northern tamandua Southern tamandua Genus †Protamandua Anteaters are one of three surviving families of a once diverse group of mammals that occupied South America while it was geographically isolated from an invasion of animals from North America, the other two being the sloths and the armadillos.
At one time, anteaters were assumed to be related to aardvarks and pangolins because of their physical similarities to those animals, but these similarities have since been determined to be not a sign of a common ancestor, but of convergent evolution. All have evolved powerful digging forearms, long tongues, toothless, tube-like snouts to subsist by raiding termite mounds; this similarity is the reason aardvarks are commonly called "anteaters". All anteaters have elongated snouts equipped with a thin tongue that can be extended to a length greater than the length of the head, they use their large, curved foreclaws to tear open ant and termite mounds and for defense, while their dense and long fur protects them from attacks from the insects. All species except the giant anteater have a long prehensile tail. Anteaters are solitary mammals prepared to defend their 1.0- to 1.5-mi2 territories. They do not enter a territory of another anteater of the same sex, but males enter the territory of associated females.
When a territorial dispute occurs, they vocalize and can sometimes sit on or ride the back of their opponents. Anteaters have poor sight but an excellent sense of smell, most species depend on the latter for foraging and defence, their hearing is thought to be good. With a body temperature fluctuating between 33 and 36 °C, like other xenarthrans, have among the lowest body temperatures of any mammal, can tolerate greater fluctuations in body temperature than most mammals, its daily energy intake from food is only greater than its energy need for daily activities, anteaters coordinate their body temperatures so they keep cool during periods of rest, heat up during foraging. Adult males are larger and more muscular than females, have wider heads and necks. Visual sex determination can, however, be difficult, since the penis and testes are located internally between the rectum and urinary bladder in males and females have a single pair of mammae near the armpits. Fertilization occurs by contact transfer without intromission, similar to some lizards.
Polygynous mating results in a single offspring. The large foreclaws prevent mothers from grasping their newborns and they therefore have to carry the offspring until they are self-sufficient. Anteaters are specialized to feed on small insects, with each anteater species having its own insect preferences: small species are specialized on arboreal insects living on small branches, while large species can penetrate the hard covering of the nests of terrestrial insects. To avoid the jaws and other defences of the invertebrates, anteaters have adopted the feeding strategy of licking up large numbers of ants and termites as as possible — an anteater spends about a minute at a nest before moving on to another — and a giant anteater has to visit up to 200 nests per hour to consume the thousands of insects it needs to satisfy its caloric requirements; the anteater's tongue is covered with thousands of tiny hooks called filiform papillae which are used to hold the insects together with large amounts of saliva.
Swallowing and the movement of the tongue are aided by side-to-side movements of the jaws. The tongue is attached to the sternum and moves quickly, flicking 150 times per minute; the anteater's stomach, similar to a bird's gizzard, has hardened folds and uses strong contractions to grind the insects. Silky anteaters and northern tamanduas extend their ranges as far north as southeastern Mexico, while giant anteaters can be found as far north as Central America. Southern tamanduas range south to Uruguay and the ranges of all species except th
The Permian is a geologic period and system which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago, to the beginning of the Triassic period 251.902 Mya. It is the last period of the Paleozoic era; the concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the city of Perm. The Permian witnessed the diversification of the early amniotes into the ancestral groups of the mammals, turtles and archosaurs; the world at the time was dominated by two continents known as Pangaea and Siberia, surrounded by a global ocean called Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, who could better cope with these drier conditions, rose to dominance in place of their amphibian ancestors; the Permian ended with the Permian–Triassic extinction event, the largest mass extinction in Earth's history, in which nearly 96% of marine species and 70% of terrestrial species died out.
It would take well into the Triassic for life to recover from this catastrophe. Recovery from the Permian–Triassic extinction event was protracted; the term "Permian" was introduced into geology in 1841 by Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Édouard de Verneuil; the region now lies in the Perm Krai of Russia. Official ICS 2017 subdivisions of the Permian System from most recent to most ancient rock layers are: Lopingian epoch Changhsingian Wuchiapingian Others: Waiitian Makabewan Ochoan Guadalupian epoch Capitanian stage Wordian stage Roadian stage Others: Kazanian or Maokovian Braxtonian stage Cisuralian epoch Kungurian stage Artinskian stage Sakmarian stage Asselian stage Others: Telfordian Mangapirian Sea levels in the Permian remained low, near-shore environments were reduced as all major landmasses collected into a single continent—Pangaea; this could have in part caused the widespread extinctions of marine species at the end of the period by reducing shallow coastal areas preferred by many marine organisms.
During the Permian, all the Earth's major landmasses were collected into a single supercontinent known as Pangaea. Pangaea straddled the equator and extended toward the poles, with a corresponding effect on ocean currents in the single great ocean, the Paleo-Tethys Ocean, a large ocean that existed between Asia and Gondwana; the Cimmeria continent rifted away from Gondwana and drifted north to Laurasia, causing the Paleo-Tethys Ocean to shrink. A new ocean was growing on its southern end, the Tethys Ocean, an ocean that would dominate much of the Mesozoic era. Large continental landmass interiors experience climates with extreme variations of heat and cold and monsoon conditions with seasonal rainfall patterns. Deserts seem to have been widespread on Pangaea; such dry conditions favored gymnosperms, plants with seeds enclosed in a protective cover, over plants such as ferns that disperse spores in a wetter environment. The first modern trees appeared in the Permian. Three general areas are noted for their extensive Permian deposits—the Ural Mountains and the southwest of North America, including the Texas red beds.
The Permian Basin in the U. S. states of Texas and New Mexico is so named because it has one of the thickest deposits of Permian rocks in the world. The climate in the Permian was quite varied. At the start of the Permian, the Earth was still in an ice age. Glaciers receded around the mid-Permian period as the climate warmed, drying the continent's interiors. In the late Permian period, the drying continued although the temperature cycled between warm and cool cycles. Permian marine deposits are rich in fossil mollusks and brachiopods. Fossilized shells of two kinds of invertebrates are used to identify Permian strata and correlate them between sites: fusulinids, a kind of shelled amoeba-like protist, one of the foraminiferans, ammonoids, shelled cephalopods that are distant relatives of the modern nautilus. By the close of the Permian, trilobites and a host of other marine groups became extinct. Terrestrial life in the Permian included diverse plants, fungi and various types of tetrapods; the period saw a massive desert covering the interior of Pangaea.
The warm zone spread in the northern hemisphere. The rocks formed at that time were stained red by iron oxides, the result of intense heating by the sun of a surface devoid of vegetation cover. A number of older types of plants and animals became marginal elements; the Permian began with the Carboniferous flora still flourishing. About the middle of the Permian a major transition in vegetation began; the swamp-loving