Natal red rock hare
The Natal red rock hare or greater red rock hare is a species of mammal in the family Leporidae. It has a grizzled, grayish brown head and reddish brown upperparts; the dense fur is thick and rougher than other rock hares. It is endemic to Africa, found in southeastern provinces of South Africa, eastern Lesotho and southern Mozambique, it is a herbivore feeding on grass. It breeds throughout the year, one or two pups are born in the summer, it is rated as a species of least concern on the IUCN Red List of Endangered Species. French zoologist Isidore Geoffroy Saint-Hilaire first described the Natal red rock hare in 1832 and classified it in the genus Lepus, giving it the name Lepus crassicaudatus. American mammalogist Marcus Ward Lyon Jr. placed the Natal red rock hare in the genus Pronolagus in 1906, it was given the name Pronolagus crassicaudatus. It was considered a subspecies of the Jameson's red rock hare. In the third edition of Mammal Species of the World published in 2005, R. S. Hoffman and A. T. Smith listed the Natal red rock hare as a separate species and included its four taxonomic synonyms: P. c. kariegae.
They described the taxonomic relationship between the Natal red rock hare and Jameson's red rock hare as unclear. The Natal red rock hare is a large hare, measuring 46 to 56 cm in length, having a 35 to 11 cm long, bright reddish brown tail lighter in tone than other members of the genus, weighing 2.4 to 3 kg. It has a grizzled, grayish brown head with gray or grayish white lower cheeks and chin, a grayish white band running laterally along the jaw edge up to the nuchal patch, it has grizzled, brown dorsal pelage flecked with black, pale reddish brown ventral pelage with non-uniform white patches and streaks. The flanks have fewer hairs, which feature black tips; the upperparts and gular collar are reddish brown in color, in contrast with the color of the chest and throat. The underparts are grizzled with rufous fur; the ears are short, measuring 7.5 to 8.5 cm in length, sparsely furred, are gray on the inner surface and whitish gray on the outer surface. The nuchal patch is brown to gray in color, the rump is bright reddish brown.
It has gray underfur. The feet pads are reddish brown, the forelimbs and hindlimbs are a dull reddish brown; the dense fur is thick and rougher than other rock hares. The flesh is reported to have an odor comparable to urine, it is similar to the Hewitt's red rock hare, shorter, has shorter ears, a longer tail. The Natal red rock hare is endemic to southern Africa, it lives in steep, rocky terrain like cliffs, hillsides with scattered rocks and boulders, stone outcrops, rocky gorges with edible grass. It takes refuge in low, dense vegetation, it is found at heights of up to 1,550 metres above sea level. The Natal red rock hare lives in small colonies consisting of a few hares, it is a nocturnal species, hides in creeks or under rocks, boulders, or dense grass during the day. It is a herbivore, feeds on grass young grass and herbs; as it obtains moisture from dew and from food, it is independent of water, but it drinks any available water. It travels to higher elevations at night to forage on grasses.
It has a good, 360 degree vision, sense of smell, hearing. On erecting its ears, a network of veins on the inner surface radiate heat to reduce the body temperature; the breeding period continues throughout the year. The nest is lined with female fur. After a gestation period of one month one or two pups weighing 70 to 100 g are born in the summer, it produces grunting calls while contacting with other members of the species, produces shrill screams and cries when alarmed. It kicks with the hindfeet when caught, it can live up to an age of five years. Its predators include all larger carnivores such as leopards, African wildcats and birds of prey. Since 1996, the Natal red rock hare has been rated as a species of least concern on the IUCN Red List of Endangered Species; this is because it is widespread, having a large range—more than 20,000 square kilometres —and although its range and population are decreasing, the number of mature individuals in the wild is above 10,000. It is abundant within its range in provincial parks, national parks, wildlife refugees, is protected by Provincial Nature Conservation agencies seasonally, as a game species.
Human activities such as encroachment of settlements and hunting in rural areas poses a threat to the Natal red rock hare, due to which its population is decreasing. Since the 1900s, more than 21% to 50% of its habitat has been destroyed, predicted to remain between 21% and 50% till 2022, decreasing its population by 20% or more by then
The lagomorphs are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae and the Ochotonidae. The name of the order is derived from the Ancient Greek lagos + morphē. There are about eighty-seven extant species of lagomorph, including about twenty-nine species of pika, twenty-eight species of rabbit and cottontail, thirty species of hare. Lagomorphs share a common ancestor with rodents, together forming the clade Glires. Like the ancestors of most modern mammalian groups, this most recent common ancestor lived after the last great extinction event, the K–Pg extinction 66 million years ago that drove all dinosaurs except birds to extinction. Early lagomorphs arose in Asia and spread across the northern hemisphere. Rodents came to dominate more environmental niches, lagomorphs seem to have been in decline. Other names used for this order, now considered synonymous, include: Duplicidentata - Illiger, 1811; the extinct family Prolagidae is represented by a single species, the Sardinian pika Prolagus sardus, fossils of which are known from Sardinia and nearby small islands.
It may have survived until about 1774. The evolutionary history of the lagomorphs is still not well understood; until it was agreed that Eurymylus, which lived in eastern Asia and dates back to the late Paleocene or early Eocene, was an ancestor of the lagomorphs. More recent examination of the fossil evidence suggests that the lagomorphs may have instead descended from Anagaloidea known as "mimotonids", while Eurymylus was more related to rodents; the leporids first appeared in the late Eocene and spread throughout the Northern Hemisphere. The pikas appeared somewhat in the Oligocene of eastern Asia. Lagomorphs were more diverse in the past than in the present, with around 75 genera and over 230 species represented in the fossil record and many more species in a single biome; this is evidence. Recent finds suggest an Indian origin for the clade, having evolved in isolation when India was an island continent in the Paleocene. Lagomorphs are similar to other mammals in that they all have hair, four limbs, mammary glands and are endothermic.
They differ in. Although lagomorphs are more related to rodents than any other mammals, the two orders still have some major differences. Lagomorphs differ from rodents. Lagomorphs are strictly herbivorous, unlike rodents, many of which will eat both meat and vegetable matter, they resemble rodents, however, in that their incisor teeth grow continuously throughout their lives, thus necessitating constant chewing on fibrous food to prevent the teeth from growing too long. To the rodents and some mammalian insectivores, they have a smooth-surfaced cerebrum. Rabbits and hares move by jumping, pushing off with their strong hind legs and using their forelimbs to soften the impact on landing. Pikas lack certain skeletal modifications present in leporids, such as a arched skull, an upright posture of the head, strong hind limbs and pelvic girdle, long limbs. Pikas have a short nasal region and lack a supraorbital foramen, while leporids have prominent supraorbital foramina and nasal regions. Pikas known as conies, are represented by the family Ochotonidae and are small mammals native to mountainous regions of western North America, Central Asia.
They are about 15 cm long and have greyish-brown, silky fur, small rounded ears, no tail. Their four legs are nearly equal in length; some species live in scree, making their homes in the crevices between broken rocks, while others construct burrows in upland areas. The rock-dwelling species are long-lived and solitary, have one or two litters of a small number of young each year and have stable populations; the burrowing species, in contrast, are short-lived and have multiple large litters during the year. These species tend to have large swings in population size; the gestation period of the pika is around one month long, the newborns are altricial– they require parental care. The social behaviour of the two groups differs: the rock dwellers aggressively maintain scent-marked territories, while the burrowers live in family groups, interact vocally with each other and defend a mutual territory. Pikas are active early and late in the day during hot weather, they feed on all sorts of plant material.
As they do not hibernate, they make "haypiles" of dried vegetation which they collect and carry back to their homes to store for use during winter. Hares, members of genus Lepus of family Leporidae, are medium size mammals native to Europe, Asia and North America. North American jackrabbits are hares. Species vary in size from 40 to 70 cm in length and have long powerful back legs, ears up to 20 cm in length. Although greyish-brown, some species turn white in winter, they are solitary animals and several litters of young are born during the year in a form, a hollow in the ground amongst dense vegetation. The young are born furred and active, they are preyed upon by large mammalian birds of prey. Rabbits, members of family Leporidae outside Lepus, are gen
Mammals are vertebrate animals constituting the class Mammalia, characterized by the presence of mammary glands which in females produce milk for feeding their young, a neocortex, fur or hair, three middle ear bones. These characteristics distinguish them from reptiles and birds, from which they diverged in the late Triassic, 201–227 million years ago. There are around 5,450 species of mammals; the largest orders are the rodents and Soricomorpha. The next three are the Primates, the Cetartiodactyla, the Carnivora. In cladistics, which reflect evolution, mammals are classified as endothermic amniotes, they are the only living Synapsida. The early synapsid mammalian ancestors were sphenacodont pelycosaurs, a group that produced the non-mammalian Dimetrodon. At the end of the Carboniferous period around 300 million years ago, 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 in the early Mesozoic era.
The modern mammalian orders arose in the Paleogene and Neogene periods of the Cenozoic era, after the extinction of non-avian dinosaurs, have been among the dominant terrestrial animal groups from 66 million years ago to the present. The basic body type is quadruped, most mammals use their four extremities for terrestrial locomotion. Mammals range in size from the 30–40 mm bumblebee bat to the 30-meter blue whale—the largest animal on the planet. Maximum lifespan varies from two years for the shrew to 211 years for the bowhead whale. All modern mammals give birth to live young, except the five species of monotremes, which are egg-laying mammals; the most species-rich group of mammals, the cohort called placentals, have a placenta, which enables the feeding of the fetus during gestation. Most mammals are intelligent, with some possessing large brains, self-awareness, tool use. Mammals can communicate and vocalize in several different ways, including the production of ultrasound, scent-marking, alarm signals and echolocation.
Mammals can organize themselves into fission-fusion societies and hierarchies—but can be solitary and territorial. Most mammals are polygynous. Domestication of many types of mammals by humans played a major role in the Neolithic revolution, resulted in farming replacing hunting and gathering as the primary source of food for humans; this led to a major restructuring of human societies from nomadic to sedentary, with more co-operation among larger and larger groups, the development of the first civilizations. Domesticated mammals provided, continue to provide, power for transport and agriculture, as well as food and leather. Mammals are hunted and raced for sport, are used as model organisms in science. Mammals have been depicted in art since Palaeolithic times, appear in literature, film and religion. Decline in numbers and extinction of many mammals is driven by human poaching and habitat destruction deforestation. Mammal classification has been through several iterations since Carl Linnaeus defined the class.
No classification system is universally accepted. George Gaylord Simpson's "Principles of Classification and a Classification of Mammals" provides systematics of mammal origins and relationships that were universally taught until the end of the 20th century. Since Simpson's classification, the paleontological record has been recalibrated, the intervening years have seen much debate and progress concerning the theoretical underpinnings of systematization itself through the new concept of cladistics. Though field work made Simpson's classification outdated, it remains the closest thing to an official classification of mammals. Most mammals, including the six most species-rich orders, belong to the placental group; the three largest orders in numbers of species are Rodentia: mice, porcupines, beavers and other gnawing mammals. The next three biggest orders, depending on the biological classification scheme used, are the Primates including the apes and lemurs. According to Mammal Species of the World, 5,416 species were identified in 2006.
These were grouped into 153 families and 29 orders. In 2008, the International Union for Conservation of Nature completed a five-year Global Mammal Assessment for its IUCN Red List, which counted 5,488 species. According to a research published in the Journal of Mammalogy in 2018, the number of recognized mammal species is 6,495 species included 96 extinct; the word "mammal" is modern, from the scientific name Mammalia coined by Carl Linnaeus in 1758, derived from the Latin mamma. In an influential 1988 paper, Timothy Rowe defined Mammalia phylogenetically as the crown group of mammals, the clade consisting of the most recent common ancestor of living monotremes and therian m
A karyotype is the number and appearance of chromosomes in the nucleus of a eukaryotic cell. The term is used for the complete set of chromosomes in a species or in an individual organism and for a test that detects this complement or measures the number. Karyotypes describe the chromosome count of an organism and what these chromosomes look like under a light microscope. Attention is paid to their length, the position of the centromeres, banding pattern, any differences between the sex chromosomes, any other physical characteristics; the preparation and study of karyotypes is part of cytogenetics. The study of whole sets of chromosomes is sometimes known as karyology; the chromosomes are depicted in a standard format known as a karyogram or idiogram: in pairs, ordered by size and position of centromere for chromosomes of the same size. The basic number of chromosomes in the somatic cells of an individual or a species is called the somatic number and is designated 2n. In the germ-line the chromosome number is n.p28 Thus, in humans 2n = 46.
So, in normal diploid organisms, autosomal chromosomes are present in two copies. There may, or may not, be sex chromosomes. Polyploid cells haploid cells have single copies; the study of karyotypes is important for cell biology and genetics, the results may be used in evolutionary biology and medicine. Karyotypes can be used for many purposes. Chromosomes were first observed in plant cells by Carl Wilhelm von Nägeli in 1842, their behavior in animal cells was described by Walther Flemming, the discoverer of mitosis, in 1882. The name was coined by another German anatomist, Heinrich von Waldeyer in 1888, it is New Latin from Ancient Greek κάρυον karyon, "kernel", "seed", or "nucleus", τύπος typos, "general form"). The next stage took place after the development of genetics in the early 20th century, when it was appreciated that chromosomes were the carrier of genes. Lev Delaunay in 1922 seems to have been the first person to define the karyotype as the phenotypic appearance of the somatic chromosomes, in contrast to their genic contents.
The subsequent history of the concept can be followed in the works of C. D. Darlington and Michael JD White. Investigation into the human karyotype took many years to settle the most basic question: how many chromosomes does a normal diploid human cell contain? In 1912, Hans von Winiwarter reported 47 chromosomes in spermatogonia and 48 in oogonia, concluding an XX/XO sex determination mechanism. Painter in 1922 was not certain whether the diploid of humans was 46 or 48, at first favoring 46, but revised his opinion from 46 to 48, he insisted on humans having an XX/XY system. Considering the techniques of the time, these results were remarkable. In textbooks, the number of human chromosomes remained at 48 for over thirty years. New techniques were needed to correct this error. Joe Hin Tjio working in Albert Levan's lab was responsible for finding the approach: Using cells in tissue culture Pretreating cells in a hypotonic solution, which swells them and spreads the chromosomes Arresting mitosis in metaphase by a solution of colchicine Squashing the preparation on the slide forcing the chromosomes into a single plane Cutting up a photomicrograph and arranging the result into an indisputable karyogram.
The work took place in 1955, was published in 1956. The karyotype of humans includes only 46 chromosomes; the great apes have 48 chromosomes. Human chromosome 2 is now known to be a result of an end-to-end fusion of two ancestral ape chromosomes; the study of karyotypes is made possible by staining. A suitable dye, such as Giemsa, is applied after cells have been arrested during cell division by a solution of colchicine in metaphase or prometaphase when most condensed. In order for the Giemsa stain to adhere all chromosomal proteins must be digested and removed. For humans, white blood cells are used most because they are induced to divide and grow in tissue culture. Sometimes observations may be made on non-dividing cells; the sex of an unborn fetus can be determined by observation of interphase cells. Six different characteristics of karyotypes are observed and compared: Differences in absolute sizes of chromosomes. Chromosomes can vary in absolute size by as much as twenty-fold between genera of the same family.
For example, the legumes Lotus tenuis and Vicia faba each have six pairs of chromosomes, yet V. faba chromosomes are many times larger. These differences reflect different amounts of DNA duplication. Differences in the position of centromeres; these differences came about through translocations. Differences in relative size of chromosomes; these differences arose from segmental interchange of unequal lengths. Differences in basic number of chromosomes; these differences could have resulted from successive unequal translocations which removed all the essential genetic material from a chromosome, permitting its loss without penalty to the organism or through fusion. Humans have one pair fewer chromosomes than the great apes. Human chromosome 2 appears to have resulted from the fusion of two ancestral chromosomes, many of the genes of those two original chromosomes have been translocated to other chromosomes. Differences in number and position of satellites. Satellites are small bodies attached to a chromosome by a thin thread.
Differences in degree and distribution of heterochromatic regions. Het
Africa is the world's second largest and second most-populous continent, being behind Asia in both categories. At about 30.3 million km2 including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area. With 1.2 billion people as of 2016, it accounts for about 16% of the world's human population. The continent is surrounded by the Mediterranean Sea to the north, the Isthmus of Suez and the Red Sea to the northeast, the Indian Ocean to the southeast and the Atlantic Ocean to the west; the continent includes various archipelagos. It contains 54 recognised sovereign states, nine territories and two de facto independent states with limited or no recognition; the majority of the continent and its countries are in the Northern Hemisphere, with a substantial portion and number of countries in the Southern Hemisphere. Africa's average population is the youngest amongst all the continents. Algeria is Africa's largest country by area, Nigeria is its largest by population. Africa central Eastern Africa, is accepted as the place of origin of humans and the Hominidae clade, as evidenced by the discovery of the earliest hominids and their ancestors as well as ones that have been dated to around 7 million years ago, including Sahelanthropus tchadensis, Australopithecus africanus, A. afarensis, Homo erectus, H. habilis and H. ergaster—the earliest Homo sapiens, found in Ethiopia, date to circa 200,000 years ago.
Africa encompasses numerous climate areas. Africa hosts a large diversity of ethnicities and languages. In the late 19th century, European countries colonised all of Africa. African nations cooperate through the establishment of the African Union, headquartered in Addis Ababa. Afri was a Latin name used to refer to the inhabitants of then-known northern Africa to the west of the Nile river, in its widest sense referred to all lands south of the Mediterranean; this name seems to have referred to a native Libyan tribe, an ancestor of modern Berbers. The name had been connected with the Phoenician word ʿafar meaning "dust", but a 1981 hypothesis has asserted that it stems from the Berber word ifri meaning "cave", in reference to cave dwellers; the same word may be found in the name of the Banu Ifran from Algeria and Tripolitania, a Berber tribe from Yafran in northwestern Libya. Under Roman rule, Carthage became the capital of the province it named Africa Proconsularis, following its defeat of the Carthaginians in the Third Punic War in 146 BC, which included the coastal part of modern Libya.
The Latin suffix -ica can sometimes be used to denote a land. The Muslim region of Ifriqiya, following its conquest of the Byzantine Empire's Exarchatus Africae preserved a form of the name. According to the Romans, Africa lay to the west of Egypt, while "Asia" was used to refer to Anatolia and lands to the east. A definite line was drawn between the two continents by the geographer Ptolemy, indicating Alexandria along the Prime Meridian and making the isthmus of Suez and the Red Sea the boundary between Asia and Africa; as Europeans came to understand the real extent of the continent, the idea of "Africa" expanded with their knowledge. Other etymological hypotheses have been postulated for the ancient name "Africa": The 1st-century Jewish historian Flavius Josephus asserted that it was named for Epher, grandson of Abraham according to Gen. 25:4, whose descendants, he claimed, had invaded Libya. Isidore of Seville in his 7th-century Etymologiae XIV.5.2. Suggests "Africa comes from the Latin aprica, meaning "sunny".
Massey, in 1881, stated that Africa is derived from the Egyptian af-rui-ka, meaning "to turn toward the opening of the Ka." The Ka is the energetic double of every person and the "opening of the Ka" refers to a womb or birthplace. Africa would be, for the Egyptians, "the birthplace." Michèle Fruyt in 1976 proposed linking the Latin word with africus "south wind", which would be of Umbrian origin and mean "rainy wind". Robert R. Stieglitz of Rutgers University in 1984 proposed: "The name Africa, derived from the Latin *Aphir-ic-a, is cognate to Hebrew Ophir." Ibn Khallikan and some other historians claim that the name of Africa came from a Himyarite king called Afrikin ibn Kais ibn Saifi called "Afrikus son of Abrahah" who subdued Ifriqiya. Africa is considered by most paleoanthropologists to be the oldest inhabited territory on Earth, with the human species originating from the continent. During the mid-20th century, anthropologists discovered many fossils and evidence of human occupation as early as 7 million years ago.
Fossil remains of several species of early apelike humans thought to have evolved into modern man, such as Australopithecus afarensis (radiometrically dated to 3.9–3.0 million years BP, Paranthropus boisei and Homo ergaster have been discovered. After the evolution of Homo sapiens sapiens 150,000 to 100,000 years BP in Africa, the continent was populated by groups of hunter-gatherers; these first modern humans left Africa and populated the rest of the globe during the Out of Africa II migration dated to 50,000 years BP, exiting the continent eith
In zoological nomenclature, a type species is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e. the species that contains the biological type specimen. A similar concept is used for suprageneric groups called a type genus. In botanical nomenclature, these terms have no formal standing under the code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus name is a specimen, the type of a species name; the species name that has that type can be referred to as the type of the genus name. Names of genus and family ranks, the various subdivisions of those ranks, some higher-rank names based on genus names, have such types. In bacteriology, a type species is assigned for each genus; every named genus or subgenus in zoology, whether or not recognized as valid, is theoretically associated with a type species. In practice, there is a backlog of untypified names defined in older publications when it was not required to specify a type.
A type species is both a concept and a practical system, used in the classification and nomenclature of animals. The "type species" represents the reference species and thus "definition" for a particular genus name. Whenever a taxon containing multiple species must be divided into more than one genus, the type species automatically assigns the name of the original taxon to one of the resulting new taxa, the one that includes the type species; the term "type species" is regulated in zoological nomenclature by article 42.3 of the International Code of Zoological Nomenclature, which defines a type species as the name-bearing type of the name of a genus or subgenus. In the Glossary, type species is defined as The nominal species, the name-bearing type of a nominal genus or subgenus; the type species permanently attaches a formal name to a genus by providing just one species within that genus to which the genus name is permanently linked. The species name in turn is fixed, to a type specimen. For example, the type species for the land snail genus Monacha is Helix cartusiana, the name under which the species was first described, known as Monacha cartusiana when placed in the genus Monacha.
That genus is placed within the family Hygromiidae. The type genus for that family is the genus Hygromia; the concept of the type species in zoology was introduced by Pierre André Latreille. The International Code of Zoological Nomenclature states that the original name of the type species should always be cited, it gives an example in Article 67.1. Astacus marinus Fabricius, 1775 was designated as the type species of the genus Homarus, thus giving it the name Homarus marinus. However, the type species of Homarus should always be cited using its original name, i.e. Astacus marinus Fabricius, 1775. Although the International Code of Nomenclature for algae and plants does not contain the same explicit statement, examples make it clear that the original name is used, so that the "type species" of a genus name need not have a name within that genus, thus in Article 10, Ex. 3, the type of the genus name Elodes is quoted as the type of the species name Hypericum aegypticum, not as the type of the species name Elodes aegyptica.
Glossary of scientific naming Genetypes – genetic sequence data from type specimens. Holotype Paratype Principle of Typification Type Type genus
Isidore Geoffroy Saint-Hilaire
Isidore Geoffroy Saint-Hilaire was a French zoologist and an authority on deviation from normal structure. In 1854 he coined the term éthologie, he was born in the son of Étienne Geoffroy Saint-Hilaire. In his earlier years he showed an aptitude for mathematics, but he devoted himself to the study of natural history and of medicine, in 1824 he was appointed assistant naturalist to his father. In 1829 he delivered for his father the second part of a course of lectures on ornithology, during the following three years he taught zoology at the Athénée, teratology at the École pratique, he was elected a member of the French Academy of Sciences in 1833, was in 1837 appointed to act as deputy for his father at the faculty of sciences in Paris. During the following year he was sent to Bordeaux to organize a similar faculty there, he became successively. In 1854 he founded the Société zoologique d'acclimatation, of which he served as president, he conducted investigations of omphalosites, hermaphroditism, etc. and is credited with introducing the term "teratologie".
From 1832 to 1837 he published his great teratological work, Histoire générale et particulière des anomalies de l’organisation chez l’homme et les animaux. Isidore Geoffroy Saint-Hilaire is commemorated in the scientific name of a species of turtle, Phrynops hilarii. Besides the above-mentioned work, he wrote: Histoire générale et particulière des anomalies de l’organisation chez l’homme et les animaux. Essais de zoologie générale. La vie Étienne Geoffroy Saint-Hilaire. Acclimatation et domestication des animaux utiles. Lettres sur particulièrement sur la viande de cheval. Histoire naturelle générale des règnes organiques, not quite completed, he was the author of various papers on zoology, comparative anatomy and palaeontology. List of Chairs of the Muséum national d'histoire naturelle This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed.. "Geoffroy Saint-Hilaire, Isidore". Encyclopædia Britannica. 11. Cambridge University Press. P. 619. Works by Isidore Geoffroy SaintHilaire at Project Gutenberg Works by or about Isidore Geoffroy Saint-Hilaire at Internet Archive Gallica Gallica has digital versions of works by Geoffroy Saint-Hilaire