romikgosai/squad_modified huggingface dataset:
The word "mammal" is modern, from the scientific name Mammalia coined by Carl Linnaeus in 1758, derived from the Latin mamma ("teat, pap"). All female mammals nurse their young with milk, which is secreted from special glands, the mammary glands. According to Mammal Species of the World, 5,416 species were known in 2006. These were grouped in 1,229 genera, 153 families and 29 orders. In 2008 the IUCN completed a five-year, 1,700-scientist Global Mammal Assessment for its IUCN Red List, which counted 5,488 accepted species.

Questions and answers:
['
Q: Who coined the name "mammal" from the scientific name Mammalia?
A: Carl Linnaeus', '
Q: What do all female mammals have in common when they have children?
A: nurse their young with milk', '
Q: How many mammals were known to exist up to 2006?
A: 5,416', '
Q: How many families did mammals consist of as of 2006?
A: 153 families']
Except for the five species of monotremes (egg-laying mammals), all modern mammals give birth to live young. Most mammals, including the six most species-rich orders, belong to the placental group. The three largest orders in numbers, are first Rodentia: mice, rats, porcupines, beavers, capybaras, and other gnawing mammals; then Chiroptera: bats; and then Soricomorpha: shrews, moles and solenodons. The next three orders, depending on the biological classification scheme used, are the Primates including the humans; the Cetartiodactyla including the whales and the even-toed hoofed mammals; and the Carnivora, that is, cats, dogs, weasels, bears, seals, and their relatives.

Questions and answers:
['
Q: How many species of mammals do not have a live birth?
A: five species', '
Q: Which group consist of the most mammals?
A: Rodentia', '
Q: Which group do humans belong too?
A: Primates', '
Q: Which group do cats and dogs belong too?
A: Carnivora']
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 sauropsid line that led to today's reptiles and birds. The line following the stem group Sphenacodontia split-off several diverse groups of non-mammalian synapsids—sometimes referred to as mammal-like reptiles—before giving rise to the proto-mammals (Therapsida) in the early Mesozoic era. The modern mammalian orders arose in the Paleogene and Neogene periods of the Cenozoic era, after the extinction of the non-avian dinosaurs 66 million years ago.

Questions and answers:
['
Q: From which time period did birds and reptiles began to appear from?
A: Carboniferous period', '
Q: When did non-avian dinosaurs become extinct?
A: 66 million years ago', '
Q: Which early mammalian ancestor produced non-mammalian Dimetroden?
A: sphenacodont pelycosaurs']
In an influential 1988 paper, Timothy Rowe defined Mammalia phylogenetically as the crown group mammals, the clade consisting of the most recent common ancestor of living monotremes (echidnas and platypuses) and therian mammals (marsupials and placentals) and all descendants of that ancestor. Since this ancestor lived in the Jurassic period, Rowe's definition excludes all animals from the earlier Triassic, despite the fact that Triassic fossils in the Haramiyida have been referred to the Mammalia since the mid-19th century.

Questions and answers:
['
Q: Who defined mammalian as the crown group mammals?
A: Timothy Rowe', "
Q: By Rowe's definition, when did he start to exclude animals?
A: Triassic", '
Q: Which group do marsupials and placentals belong to?
A: therian mammals']
If Mammalia is considered as the crown group, its origin can be roughly dated as the first known appearance of animals more closely related to some extant mammals than to others. Ambondro is more closely related to monotremes than to therian mammals while Amphilestes and Amphitherium are more closely related to the therians; as fossils of all three genera are dated about 167 million years ago in the Middle Jurassic, this is a reasonable estimate for the appearance of the crown group. The earliest known synapsid satisfying Kemp's definitions is Tikitherium, dated 225 Ma, so the appearance of mammals in this broader sense can be given this Late Triassic date. In any case, the temporal range of the group extends to the present day.

Questions and answers:
["
Q: Which group are Ambondro's closely related to?
A: monotremes", '
Q: Which two groups are closely related to therian mammals?
A: Amphilestes and Amphitherium', '
Q: How many years do momotremes and therian mammals go back?
A: 167 million years', '
Q: About what year do synapsid date back to?
A: 225 Ma']
George Gaylord Simpson's "Principles of Classification and a Classification of Mammals" (AMNH Bulletin v. 85, 1945) was the original source for the taxonomy listed here. Simpson laid out a systematics of mammal origins and relationships that was universally taught until the end of the 20th century. Since Simpson's classification, the paleontological record has been recalibrated, and the intervening years have seen much debate and progress concerning the theoretical underpinnings of systematization itself, partly through the new concept of cladistics. Though field work gradually made Simpson's classification outdated, it remained the closest thing to an official classification of mammals.

Questions and answers:
['
Q: Who wrote the "Principles of Classification and a Classification of Mammals?
A: George Gaylord Simpson', '
Q: Simpson laid the systematics of mammal origins and was taught universally up until the end of what century?
A: 20th', '
Q: Which new concept has greatly taken over Simpsons much debated theoretical systematization?
A: cladistics']
In 1997, the mammals were comprehensively revised by Malcolm C. McKenna and Susan K. Bell, which has resulted in the McKenna/Bell classification. Their 1997 book, Classification of Mammals above the Species Level, is the most comprehensive work to date on the systematics, relationships, and occurrences of all mammal taxa, living and extinct, down through the rank of genus, though recent molecular genetic data challenge several of the higher level groupings. The authors worked together as paleontologists at the American Museum of Natural History, New York. McKenna inherited the project from Simpson and, with Bell, constructed a completely updated hierarchical system, covering living and extinct taxa that reflects the historical genealogy of Mammalia.

Questions and answers:
['
Q: In 1997 who revised the classification of mammals?
A: Malcolm C. McKenna and Susan K. Bell', '
Q: Where did the two authors work together as paleontologist? 
A: American Museum of Natural History', '
Q: From whom did McKenna inherit the project from?
A: Simpson']
Molecular studies based on DNA analysis have suggested new relationships among mammal families over the last few years. Most of these findings have been independently validated by retrotransposon presence/absence data. Classification systems based on molecular studies reveal three major groups or lineages of placental mammals- Afrotheria, Xenarthra, and Boreoeutheria- which diverged from early common ancestors in the Cretaceous. The relationships between these three lineages is contentious, and all three possible different hypotheses have been proposed with respect to which group is basal with respect to other placentals. These hypotheses are Atlantogenata (basal Boreoeutheria), Epitheria (basal Xenarthra), and Exafroplacentalia (basal Afrotheria). Boreoeutheria in turn contains two major lineages- Euarchontoglires and Laurasiatheria.

Questions and answers:
['
Q: Through Molecular studies, what was used to suggest new relationships among mammal families?
A: DNA analysis', '
Q: During these Molecular studies, which three major groups of mammals shared a common ancestors from the Cretaceous period?
A: Afrotheria, Xenarthra, and Boreoeutheria', '
Q: Afrotheria,Xenartha, and Boreoeutheria deprives from which two lineages?
A: Euarchontoglires and Laurasiatheria']
The first amniotes apparently arose in the Late Carboniferous. They descended from earlier reptiliomorph amphibious tetrapods, which lived on land that was already inhabited by insects and other invertebrates as well as by ferns, mosses and other plants. Within a few million years, two important amniote lineages became distinct: the synapsids, which would later include the common ancestor of the mammals; and the sauropsids, which would eventually come to include turtles, lizards, snakes, crocodilians, dinosaurs and birds. Synapsids have a single hole (temporal fenestra) low on each side of the skull.

Questions and answers:
['
Q: From which period did the first known amniotes arise from?
A: Carboniferous', '
Q: From which group did amniotes descendents of?
A: reptiliomorph amphibious tetrapods', '
Q: Two important Amniotes  lineages became distinct, what was the name of that distinction?
A: the synapsids', '
Q: Sauropsids would later include which other animals into its group?
A: turtles, lizards, snakes, crocodilians, dinosaurs and birds', '
Q: What is a distinct trait of Synapsids?
A: single hole (temporal fenestra) low on each side of the skull']
Therapsids descended from pelycosaurs in the Middle Permian, about 265 million years ago, and became the dominant land vertebrates. They differ from basal eupelycosaurs in several features of the skull and jaws, including: larger temporal fenestrae and incisors which are equal in size. The therapsid lineage leading to mammals went through a series of stages, beginning with animals that were very like their pelycosaur ancestors and ending with probainognathian cynodonts, some of which could easily be mistaken for mammals. Those stages were characterized by:

Questions and answers:
['
Q: From which dinosaur group did Therapsids descend from?
A: pelycosaurs', '
Q: Around what time did Therapsids become the dominant land animal?
A: 265 million years ago', '
Q: At which group did Therapsids end with?
A: probainognathian cynodonts']
The Permian–Triassic extinction event, which was a prolonged event due to the accumulation of several extinction pulses, ended the dominance of the carnivores among the therapsids. In the early Triassic, all the medium to large land carnivore niches were taken over by archosaurs which, over an extended period of time (35 million years), came to include the crocodylomorphs, the pterosaurs, and the dinosaurs. By the Jurassic, the dinosaurs had come to dominate the large terrestrial herbivore niches as well.

Questions and answers:
['
Q: What was the name of extinction level event that ended the dominance of the carnivores among therapsids?
A: Permian–Triassic', '
Q: During which time period did archosaurs begin to take over as the dominant carnivore?
A: Triassic', '
Q: Which three groups did the early Triassic period consist of?
A: crocodylomorphs, the pterosaurs, and the dinosaurs', '
Q: During the Jurassic period which group came out as the most dominate for both carnivores and herbivores?
A: dinosaurs']
The oldest known fossil among the Eutheria ("true beasts") is the small shrewlike Juramaia sinensis, or "Jurassic mother from China", dated to 160 million years ago in the Late Jurassic. A later eutherian, Eomaia, dated to 125 million years ago in the Early Cretaceous, possessed some features in common with the marsupials but not with the placentals, evidence that these features were present in the last common ancestor of the two groups but were later lost in the placental lineage. In particular:

Questions and answers:
['
Q: What is the oldest know fossil among the Eutheria group? 
A: shrewlike Juramaia sinensis', '
Q: How long ago does oldest know fossil date back to?
A: 160 million years ago', '
Q: In what time period did early animals share some features with marsupials?
A: 125 million years ago', '
Q: Which lineage were some of these early marsupial features were lost?
A: placental']
Recent molecular phylogenetic studies suggest that most placental orders diverged about 100 to 85 million years ago and that modern families appeared in the period from the late Eocene through the Miocene. But paleontologists object that no placental fossils have been found from before the end of the Cretaceous. The earliest undisputed fossils of placentals come from the early Paleocene, after the extinction of the dinosaurs. In particular, scientists have recently identified an early Paleocene animal named Protungulatum donnae as one of the first placental mammals. The earliest known ancestor of primates is Archicebus achilles from around 55 million years ago. This tiny primate weighed 20–30 grams (0.7–1.1 ounce) and could fit within a human palm.

Questions and answers:
['
Q: How long ago did most placental orders diverge from?
A: 100 to 85 million years ago', '
Q: Which two major time periods did placentals appear?
A: Eocene through the Miocene', '
Q: Which time period did early highly undisputed fossils of placental mammals appear?
A: Paleocene', '
Q: When is the earliest know primate thought to had exist?
A: 55 million years ago', '
Q: How much did the first primate weigh?
A: 20–30 grams (0.7–1.1 ounce)']
The earliest clear evidence of hair or fur is in fossils of Castorocauda, from 164 million years ago in the Middle Jurassic. In the 1950s, it was suggested that the foramina (passages) in the maxillae and premaxillae (bones in the front of the upper jaw) of cynodonts were channels which supplied blood vessels and nerves to vibrissae (whiskers) and so were evidence of hair or fur; it was soon pointed out, however, that foramina do not necessarily show that an animal had vibrissae, as the modern lizard Tupinambis has foramina that are almost identical to those found in the nonmammalian cynodont Thrinaxodon. Popular sources, nevertheless, continue to attribute whiskers to Thrinaxodon.

Questions and answers:
['
Q: When is it believed that the earliest know hair was said to exist?
A: 164 million years ago', '
Q: When was it suggested that foramina premaxillae could contain the first know hairs?
A: 1950s', '
Q: Which major time period were these suggested hairs from?
A: Jurassic']
When endothermy first appeared in the evolution of mammals is uncertain. Modern monotremes have lower body temperatures and more variable metabolic rates than marsupials and placentals, but there is evidence that some of their ancestors, perhaps including ancestors of the therians, may have had body temperatures like those of modern therians. Some of the evidence found so far suggests that Triassic cynodonts had fairly high metabolic rates, but it is not conclusive. For small animals, an insulative covering like fur is necessary for the maintenance of a high and stable body temperature.

Questions and answers:
['
Q: Which group of animal has a lower body temperature that marsupials and placentals?
A: monotremes', '
Q: Which time period is suggested that cynodonts had a high metabolic rate?
A: Triassic', '
Q: Why is it necessary for smaller animals to have an insulative covering?
A: maintenance of a high and stable body temperature']
Breathing is largely driven by the muscular diaphragm, which divides the thorax from the abdominal cavity, forming a dome with its convexity towards the thorax. Contraction of the diaphragm flattens the dome, increasing the volume of the cavity in which the lung is enclosed. Air enters through the oral and nasal cavities; it flows through the larynx, trachea and bronchi and expands the alveoli. Relaxation of the diaphragm has the opposite effect, passively recoiling during normal breathing. During exercise, the abdominal wall contracts, increasing visceral pressure on the diaphragm, thus forcing the air out more quickly and forcefully. The rib cage itself also is able to expand and contract the thoracic cavity to some degree, through the action of other respiratory and accessory respiratory muscles. As a result, air is sucked into or expelled out of the lungs, always moving down its pressure gradient. This type of lung is known as a bellows lung as it resembles a blacksmith's bellows. Mammals take oxygen into their lungs, and discard carbon dioxide.

Questions and answers:
['
Q: When air enters both the oral and nasal cavities, where does it flow through?
A: larynx, trachea and bronchi', '
Q: Increasing pressure on the diaphragm thus increasing air output more frequently is usually caused by?
A: exercise', '
Q: A result of air being sucked into or blown out of the lung thats moving its pressure gradient is referred to?
A: bellows lung', "
Q: Where did the term Bellows Lung come from?
A: blacksmith's bellows"]
The epidermis is typically 10 to 30 cells thick; its main function is to provide a waterproof layer. Its outermost cells are constantly lost; its bottommost cells are constantly dividing and pushing upward. The middle layer, the dermis, is 15 to 40 times thicker than the epidermis. The dermis is made up of many components, such as bony structures and blood vessels. The hypodermis is made up of adipose tissue. Its job is to store lipids, and to provide cushioning and insulation. The thickness of this layer varies widely from species to species.

Questions and answers:
['
Q: What is the typical thickness of the epidermis?
A: 10 to 30 cells thick', '
Q: What is the main function of the epidermis?
A: to provide a waterproof layer', '
Q: How much more thicker is the dermis to the epidermis?
A: 15 to 40 times thicker', '
Q: What is the dermis mainly consist of?
A: bony structures and blood vessels', '
Q: What does the Hyperdermis consist of?
A: adipose tissue']
Mammalian hair, also known as pelage, can vary in color between populations, organisms within a population, and even on the individual organism. Light-dark color variation is common in the mammalian taxa. Sometimes, this color variation is determined by age variation, however, in other cases, it is determined by other factors. Selective pressures, such as ecological interactions with other populations or environmental conditions, often lead to the variation in mammalian coloration. These selective pressures favor certain colors in order to increase survival. Camouflage is thought to be a major selection pressure shaping coloration in mammals, although there is also evidence that sexual selection, communication, and physiological processes may influence the evolution of coloration as well. Camouflage is the most predominant mechanism for color variation, as it aids in the concealment of the organisms from predators or from their prey. Coat color can also be for intraspecies communication such as warning members of their species about predators, indicating health for reproductive purposes, communicating between mother and young, and intimidating predators. Studies have shown that in some cases, differences in female and male coat color could indicate information nutrition and hormone levels, which are important in the mate selection process. One final mechanism for coat color variation is physiological response purposes, such as temperature regulation in tropical or arctic environments. Although much has been observed about color variation, much of the genetic that link coat color to genes is still unknown. The genetic sites where pigmentation genes are found are known to affect phenotype by: 1) altering the spatial distribution of pigmentation of the hairs, and 2) altering the density and distribution of the hairs. Quantitative trait mapping is being used to better understand the distribution of loci responsible for pigmentation variation. However, although the genetic sites are known, there is still much to learn about how these genes are expressed.

Questions and answers:
['
Q: What is another name used for mammalian hair?
A: pelage', '
Q: Which color of hair is most common among mammalian taxa?
A: Light-dark color', '
Q: Besides Camouflage being a reason for having certain hair colors, what other reasons have been discovered? 
A: sexual selection, communication, and physiological processes']
Most mammals are viviparous, giving birth to live young. However, the five species of monotreme, the platypuses and the echidnas, lay eggs. The monotremes have a sex determination system different from that of most other mammals. In particular, the sex chromosomes of a platypus are more like those of a chicken than those of a therian mammal. Like marsupials and most other mammals, monotreme young are larval and fetus-like, as the presence of epipubic bones prevents the expansion of the torso, forcing them to produce small young.

Questions and answers:
['
Q: What is the common mammal group that gives birth to live young?
A: viviparous', '
Q: How many species of mammals lay eggs?
A: five species', '
Q: Which mammal that has the bill of a duck lays eggs?
A: platypus', '
Q: The platypus has sex chromosomes more related to which other non-mammal?
A: chicken']
Viviparous mammals are in the subclass Theria; those living today are in the marsupial and placental infraclasses. A marsupial has a short gestation period, typically shorter than its estrous cycle, and gives birth to an undeveloped newborn that then undergoes further development; in many species, this takes place within a pouch-like sac, the marsupium, located in the front of the mother's abdomen. This is the plesyomorphic condition among viviparous mammals; the presence of epipubic bones in all non-placental mammals prevents the expansion of the torso needed for full pregnancy. Even non-placental eutherians probably reproduced this way.

Questions and answers:
['
Q: Which sub class are most viviparous mammals in?
A: Theria', '
Q: Viviparous mammals today are in which two main infraclasses?
A: marsupial and placental', '
Q: What is present in all non-placental mammals?
A: epipubic bones']
In intelligent mammals, such as primates, the cerebrum is larger relative to the rest of the brain. Intelligence itself is not easy to define, but indications of intelligence include the ability to learn, matched with behavioral flexibility. Rats, for example, are considered to be highly intelligent, as they can learn and perform new tasks, an ability that may be important when they first colonize a fresh habitat. In some mammals, food gathering appears to be related to intelligence: a deer feeding on plants has a brain smaller than a cat, which must think to outwit its prey.

Questions and answers:
['
Q: Which part is larger relative to the brain in primates?
A: cerebrum', '
Q: Which non-primate has the ability to learn and perform new task?
A: Rats', '
Q: Mammals with smaller brains tend to be in what class in the food chain?
A: prey']