The Coquerel's sifaka is a diurnal, medium-sized lemur of the sifaka genus Propithecus. It is native to Madagascar; the Coquerel's sifaka was once considered to be a subspecies of the Verreaux's sifaka, but was granted full species level. Coquerel's sifaka is a vertical clinger and leaper with long, powerful hind legs and an upright posture, it has a head-body length of 42 -- a tail length of 50 -- 60 cm. The total mature length is 93 to 110 cm. Adult body mass is around 4 kg; the dorsal pelage and tail are white, with portions of the limbs. The coat is dense, its face is black except for a distinctive patch of white fur along the bridge of the nose. Its naked ears are black, its eyes are yellow or orange; the bottom of the lemurs hands and feet are black, while the thighs and chest are a chocolate brown. Like all lemurs, Coquerel’s Sifaka’s have a toothcomb, they use it for grooming and sometimes scraping fruit off a pit. This species occurs at altitudes of less than 300 ft in the dry deciduous forests of northwestern Madagascar, including coastal forests.
It occurs from the Betsiboka River, up to the Maevarano River, are common in large area between these rivers. A extensive survey of the species distribution conducted in 2009, 2010 and 2011 led to the confirmation of its presence in most forest fragments between the two above-mentioned rivers, its eastern distribution limits are unclear, between the Sofia and Bemarivo rivers, the species has twice been reported to be absent. The southern part of the inter-river system between the Bemarivo and Betsiboka rivers, where little is known about the presence of the species, requires surveys. Groups of this species have a home range area amounting to 4-9 hectares. A 2014 line transect distance sampling work in Ankarafantsika National Park suggests that population densities ranges from 5 to 100 ind/km²) and significant effects of road, forest edge, and/or a effect of river proximity on densities; the population size may be ~47,000 individuals in the Ankarafantsika National Park. However, the species is seen around villages and in areas dominated by introduced tree species.
Coquerel's sifaka has an herbivorous diet. In the wet season, it eats immature leaves, fruit and dead wood. In the dry season, it eats mature buds, it may browse nearly 100 plant species, but the majority of its feeding time will be concentrated on about 10% of these. Since it has a fibrous diet, Coquerel's sifaka has an enlarged cecum and long colon that helps facilitate digestion; these lemurs spend between thirty and forty percent of their day foraging in the morning and evening. Females take leadership roles during foraging and exert their dominance by eating the preferred food or denying the males food until they are satisfied; these lemurs are beneficial to the environment because they aid seed dispersion and serve to populate the plant life. Captive Coquerel's sifkas eat shining leaf mimosa. Coquerel's sifaka lives in matriarchal groups of about three to ten individuals, it is diurnal and arboreal. Much is known about its behavior in captivity. Coquerel's sifaka spend the majority of its time in areas of three hectares.
However, they can live in areas with four to eight. Though their home range may overlap with other groups of sifaka, they avoid each other to avoid aggression; when friendly Coquerel's sifakas meet, they greet by rubbing their noses together. Matriarchy is common among lemurs. A matriarchal system is pronounced in Coquerel's sifaka. All adult and most subadult females are dominant over males. Females have preferential access to food and other resources; when a female is browsing an area or tree, a male waits for her to finish before he moves there to feed. If he gets in the way of the female, she may bite him; the male exhibits submissive behavior by rolling his tail between his legs and baring his teeth in a grimace before leaping out of her way. When mating, Coquerel's sifaka practices polyandry. A female may choose to mate with only one male, but most she will mate with several, from other visiting groups as well as from her own. Males compete for access to sexually receptive females. However, the winner of a fight will not be the one she selects to breed with.
The criteria by which she chooses a mate are evidently more complex. In some other animals, polyandrous mating is thought to raise the chances of successful fertilization, but this does not appear to be the case in Coquerel's sifaka. Instead, polyandry is thought to be advantageous because when paternity is confused, the likelihood of male infanticide decreases. Female Coquerel's sifakas choose who they mate with whether it be intragroup males or males from outside groups, they have synchronized estrous in February. Infants are born in July after a gestation period of about 162 days. One infant is born during Madagascar’s dry season. Newborn lemurs have an average weight of 100 grams, though it can vary between 115 grams. An infant will cling to its mother's chest until about a month or so after birth transfer to her back. Infants are weaned and become independent by about six months of age. Adult size is reached anywhere from one to five years. Males and females become sexually mature around two- to three-and-a-half years old, though some do not have their first offspring until they are six.
Hybrid species have been known
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals have mouthparts adapted to rasping or grinding. Horses and other herbivores have wide flat teeth that are adapted to grinding grass, tree bark, other tough plant material. A large percentage of herbivores have mutualistic gut flora that help them digest plant matter, more difficult to digest than animal prey; this flora is made up of cellulose-digesting bacteria. Herbivore is the anglicized form of a modern Latin coinage, cited in Charles Lyell's 1830 Principles of Geology. Richard Owen employed the anglicized term in an 1854 work on fossil skeletons. Herbivora is derived from the Latin herba meaning a small plant or herb, vora, from vorare, to eat or devour. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants and photosynthesizing bacteria.
More organisms that feed on autotrophs in general are known as primary consumers. Herbivory is limited to animals that eat plants. Fungi and protists that feed on living plants are termed plant pathogens, while fungi and microbes that feed on dead plants are described as saprotrophs. Flowering plants that obtain nutrition from other living plants are termed parasitic plants. There is, however, no single exclusive and definitive ecological classification of consumption patterns. In zoology, an herbivore is an animal, adapted to eat plant matter. Our understanding of herbivory in geological time comes from three sources: fossilized plants, which may preserve evidence of defence, or herbivory-related damage. Although herbivory was long thought to be a Mesozoic phenomenon, fossils have shown that within less than 20 million years after the first land plants evolved, plants were being consumed by arthropods. Insects fed on the spores of early Devonian plants, the Rhynie chert provides evidence that organisms fed on plants using a "pierce and suck" technique.
During the next 75 million years, plants evolved a range of more complex organs, such as roots and seeds. There is no evidence of any organism being fed upon until the middle-late Mississippian, 330.9 million years ago. There was a gap of 50 to 100 million years between the time each organ evolved and the time organisms evolved to feed upon them. Further than their arthropod status, the identity of these early herbivores is uncertain. Hole feeding and skeletonisation are recorded in the early Permian, with surface fluid feeding evolving by the end of that period. Herbivory among four-limbed terrestrial vertebrates, the tetrapods developed in the Late Carboniferous. Early tetrapods were large amphibious piscivores. While amphibians continued to feed on fish and insects, some reptiles began exploring two new food types and plants; the entire dinosaur order ornithischia was composed with herbivores dinosaurs. Carnivory was a natural transition from insectivory for medium and large tetrapods, requiring minimal adaptation.
In contrast, a complex set of adaptations was necessary for feeding on fibrous plant materials. Arthropods evolved herbivory in four phases, changing their approach to it in response to changing plant communities. Tetrapod herbivores made their first appearance in the fossil record of their jaws near the Permio-Carboniferous boundary 300 million years ago; the earliest evidence of their herbivory has been attributed to dental occlusion, the process in which teeth from the upper jaw come in contact with teeth in the lower jaw is present. The evolution of dental occlusion led to a drastic increase in plant food processing and provides evidence about feeding strategies based on tooth wear patterns. Examination of phylogenetic frameworks of tooth and jaw morphologes has revealed that dental occlusion developed independently in several lineages tetrapod herbivores; this suggests that evolution and spread occurred within various lineages. Herbivores form an important link in the food chain because they consume plants in order to digest the carbohydrates photosynthetically produced by a plant.
Carnivores in turn consume herbivores for the same reason, while omnivores can obtain their nutrients from either plants or animals. Due to a herbivore's ability to survive on tough and fibrous plant matter, they are termed the primary consumers in the food cycle. Herbivory and omnivory can be regarded as special cases of Consumer-Resource Systems. Herbivores come in all sizes in the animal kingdom, they include aquatic and non-aquatic vertebrates. They can be large, like an elephant. Many herbivores found living in close proximity to humans, such as rodents, cows and camels. Two herbivore feeding strategies are browsing. For a terrestrial mammal to be called a grazer, at least 90% of the forage has to be grass, for a browser at least 90% tree leaves and/or twigs. An intermediate feeding strategy is called "mixed-feeding". In their daily need to take up energy from forage, herbivores of different body mass may be selective in choosing their food. "Selective" means that herbivores may choose their forage source depending on, e.g. season or food avail
The crowned sifaka is a sifaka endemic to western Madagascar. It is of comparable size to the Golden-crowned sifaka and up to a meter in length, of which 47-57 centimeters are tail; the species is an arboreal vertical climber and leaper whose diet consists of leaves and flowers. It is threatened by habitat destruction and classified as Endangered by the IUCN; the crowned sifaka was believed to be a subspecies of either Verreaux's sifaka or Von der Decken's sifaka, but is now considered a valid species following a 2007 analysis of the cranium. The Crowned sifaka is a medium-sized sifaka who has a total length of 87 to 102 centimeters, of which 47-57 centimeters are tail, 39.5 - 45.5 cm are the head and body. Males weigh 3.5-5.0 kg for females. It is a sifaka of comparable size to the Golden-crowned sifaka, Von der Decken's sifaka and Verreaux's sifaka; the crowned sifaka is characterized by a creamy white body with tinges of golden brown around the shoulder region, upper chest and back with a dark chocolate or black head with white ear tufts.
Their dark grey face is hairless and they have a white tail. A pale patch across the bridge of the nose may be present. Crown sifaka color variations occur more in the lower regions of the sifakas range between the Mahavavy and Manombolo rivers. Melanistic forms have been documented, with most occurrences observed where the southern limit of its range overlaps with that of P. deckenii. The crowned sifaka is found in the mangroves and dry deciduous and riparian forests of northwest Madagascar. Surveys have shown in the northern range of its habitat the crowned sifaka inhabits the forest between the Mahavavy River and Betsiboka River and extending south to the region of fragmented forests around the Tsiribihina River, Mahajilo River, Mania River. Total population size in 2014 was estimated as 4,000-36,000 individuals, at densities of 46-309 individuals/km2 in different-sized forest fragments, with an average group size of 2-8 individuals per group. Estimates remain uncertain. Total area of occupancy is thought to be 2,690-4,493 km2.
The crowned sifaka is a diurnal animal active during the day. It spends a majority of its time resting with the remainder devoted to feeding, it frequents the upper stories of large trees and is found in tree crowns. Depending on season, it feeds on young or mature leaves and unripe fruits and great quantities of flowers. Group size is between 2 and 8 individuals and contains a balanced number of females and males in each group. One dominant female is found in each group. Social behavior within groups entails allogrooming of other group members, agonistic behavior, play as well as scent marking and call-localization. Reproduction is seasonal, with gestation lasting 5 -- estrus lasting 4 months. Within the typical estrus period a female may have 3-5 estruses per reproductive season. Reproduction in the crowned sifaka has been observed, what little is known about it has been documented in the captive population at the Paris Zoological Park; the restricted range and fragmented populations of the crowned sifaka are major concerns for the continuation of this species.
Habitat destruction, forest fragmentation and burn agriculture, capture for illegal pet trade, illegal hunting constitute major threats. The species is listed by the IUCN Red List as Endangered, is listed as CITES Appendix I; some of the larger populations are found in protected areas, however much of its range remain unexplored as they are labeled as politically “dangerous” zones. The 2009 Malagasy political crisis led to lawlessness across Madagascar and led to increased poaching of the sifaka for food as a delicacy in restaurants; as of 2014 there is only one successful captive breeding population of crowned sifaka in the Paris Zoological Park in Paris, France
Strepsirrhini or Strepsirhini is a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar and pottos from Africa, the lorises from India and southeast Asia. Collectively they are referred to as strepsirrhines. Belonging to the suborder are the extinct adapiform primates that thrived during the Eocene in Europe, North America, Asia, but disappeared from most of the Northern Hemisphere as the climate cooled. Adapiforms are sometimes referred to as being "lemur-like", although the diversity of both lemurs and adapiforms does not support this comparison. Strepsirrhines are defined by their "wet" rhinarium - hence the colloquial but inaccurate term "wet-nosed" - similar to the rhineria of dogs and cats, they have a smaller brain than comparably sized simians, large olfactory lobes for smell, a vomeronasal organ to detect pheromones, a bicornuate uterus with an epitheliochorial placenta. Their eyes contain a reflective layer to improve their night vision, their eye sockets include a ring of bone around the eye, but they lack a wall of thin bone behind it.
Strepsirrhine primates produce their own vitamin C, whereas haplorhine primates must obtain it from their diets. Lemuriform primates are characterized by a toothcomb, a specialized set of teeth in the front, lower part of the mouth used for combing fur during grooming. Many of today's living strepsirrhines are endangered due to habitat destruction, hunting for bushmeat, live capture for the exotic pet trade. Both living and extinct strepsirrhines are behaviorally diverse, although all are arboreal. Most living lemuriforms are nocturnal. Both living and extinct groups fed on fruit and insects; the taxonomic name Strepsirrhini derives from the Greek στρεψίς" and ῥινός, which refers to the appearance of the sinuous nostrils on the rhinarium or wet nose. The name was first used by French naturalist Étienne Geoffroy Saint-Hilaire in 1812 as a subordinal rank comparable to Platyrrhini and Catarrhini. In his description, he mentioned "Les narines terminales et sinueuses"; when British zoologist Reginald Innes Pocock revived Strepsirrhini and defined Haplorhini in 1918, he omitted the second "r" from both, although he did not remove the second "r" from Platyrrhini or Catarrhini, both of which were named by É.
Geoffroy in 1812. Following Pocock, many researchers continued to spell Strepsirrhini with a single "r" until primatologists Paulina Jenkins and Prue Napier pointed out the error in 1987. Strepsirrhines include the extinct adapiforms and the lemuriform primates, which include lemurs and lorisoids. Strepsirrhines diverged from the haplorhine primates near the beginning of the primate radiation between 55 and 90 mya. Older divergence dates are based on genetic analysis estimates, while younger dates are based on the scarce fossil record. Lemuriform primates may have evolved from either cercamoniines or sivaladapids, both of which were adapiforms that may have originated in Asia, they were once thought to have evolved from adapids, a more specialized and younger branch of adapiform from Europe. Lemurs rafted from Africa to Madagascar between 47 and 54 mya, whereas the lorises split from the African galagos around 40 mya and colonized Asia; the lemuriforms, the lemurs of Madagascar, are portrayed inappropriately as "living fossils" or as examples of "basal", or "inferior" primates.
These views have hindered the understanding of mammalian evolution and the evolution of strepsirrhine traits, such as their reliance on smell, characteristics of their skeletal anatomy, their brain size, small. In the case of lemurs, natural selection has driven this isolated population of primates to diversify and fill a rich variety of ecological niches, despite their smaller and less complex brains compared to simians; the divergence between strepsirrhines and tarsiers followed immediately after primates first evolved. Although few fossils of living primate groups – lemuriforms and simians – are known from the Early to Middle Eocene, evidence from genetics and recent fossil finds both suggest they may have been present during the early adaptive radiation; the origin of the earliest primates that the simians and tarsiers both evolved from is a mystery. Both their place of origin and the group from which they emerged are uncertain. Although the fossil record demonstrating their initial radiation across the Northern Hemisphere is detailed, the fossil record from the tropics is sparse around the time that primates and other major clades of eutherian mammals first appeared.
Lacking detailed tropical fossils and primatologists have used genetic analyses to determine the relatedness between primate lineages and the amount of time since they diverged. Using this molecular clock, divergence dates for the major primate lineages have suggested that primates evolved more than 80–90 mya, nearly 40 million years before the first examples appear in the fossil record; the early primates include both nocturnal and diurnal small-bodied species, all were arboreal, with hands and feet specially adapted for maneuvering on small branches. Plesiadapiforms from the early Paleocene are sometimes considered "archaic primates", because their teeth rese
Animals are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 millionths of a metre to 33.6 metres and have complex interactions with each other and their environments, forming intricate food webs. The category includes humans, but in colloquial use the term animal refers only to non-human animals; the study of non-human animals is known as zoology. Most living animal species are in the Bilateria, a clade whose members have a bilaterally symmetric body plan; the Bilateria include the protostomes—in which many groups of invertebrates are found, such as nematodes and molluscs—and the deuterostomes, containing the echinoderms and chordates.
Life forms interpreted. Many modern animal phyla became established in the fossil record as marine species during the Cambrian explosion which began around 542 million years ago. 6,331 groups of genes common to all living animals have been identified. Aristotle divided animals into those with those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between animal taxa. Humans make use of many other animal species for food, including meat and eggs. Dogs have been used in hunting, while many aquatic animals are hunted for sport.
Non-human animals have appeared in art from the earliest times and are featured in mythology and religion. The word "animal" comes from the Latin animalis, having soul or living being; the biological definition includes all members of the kingdom Animalia. In colloquial usage, as a consequence of anthropocentrism, the term animal is sometimes used nonscientifically to refer only to non-human animals. Animals have several characteristics. Animals are eukaryotic and multicellular, unlike bacteria, which are prokaryotic, unlike protists, which are eukaryotic but unicellular. Unlike plants and algae, which produce their own nutrients animals are heterotrophic, feeding on organic material and digesting it internally. With few exceptions, animals breathe oxygen and respire aerobically. All animals are motile during at least part of their life cycle, but some animals, such as sponges, corals and barnacles become sessile; the blastula is a stage in embryonic development, unique to most animals, allowing cells to be differentiated into specialised tissues and organs.
All animals are composed of cells, surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. During development, the animal extracellular matrix forms a flexible framework upon which cells can move about and be reorganised, making the formation of complex structures possible; this may be calcified, forming structures such as shells and spicules. In contrast, the cells of other multicellular organisms are held in place by cell walls, so develop by progressive growth. Animal cells uniquely possess the cell junctions called tight junctions, gap junctions, desmosomes. With few exceptions—in particular, the sponges and placozoans—animal bodies are differentiated into tissues; these include muscles, which enable locomotion, nerve tissues, which transmit signals and coordinate the body. There is an internal digestive chamber with either one opening or two openings. Nearly all animals make use of some form of sexual reproduction, they produce haploid gametes by meiosis.
These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In sponges, blastula larvae swim to a new location, attach to the seabed, develop into a new sponge. In most other groups, the blastula undergoes more complicated rearrangement, it first invaginates to form a gastrula with a digestive chamber and two separate germ layers, an external ectoderm and an internal endoderm. In most cases, a third germ layer, the mesoderm develops between them; these germ layers differentiate to form tissues and organs. Repeated instances of mating with a close relative during sexual reproduction leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. Animals have evolved numerous mechanisms for avoiding close inbreeding. In some species, such as the splendid fairywren, females benefit by mating with multiple males, thus producing more offspring of higher genetic quality; some animals are capable of asexual reproduction, which results
The indri called the babakoto, is one of the largest living lemurs, with a head-and-body length of about 64–72 cm and a weight of between 6 to 9.5 kg. It maintains an upright posture when climbing or clinging, it is monogamous and lives in small family groups, moving through the canopy, is purely herbivorous, feeding on leaves but seeds and flowers. The groups are quite vocal, communicating with other groups by singing and other vocalisations, it is a diurnal tree-dweller related to the sifakas and, like all lemurs, it is native to Madagascar. It is revered by the Malagasy people and plays an important part in their myths and legends with various stories in existence accounting for its origin; the main threats faced by the indri are habitat destruction and fragmentation due to slash and burn agriculture, fuelwood gathering, logging. It is hunted despite taboos against this; the International Union for Conservation of Nature has rated its conservation status as "critically endangered". The name "indri" most comes from a native Malagasy name for the animal, endrina.
An oft-repeated, but incorrect story is that the name comes from indry, meaning "there" or "there it is". French naturalist Pierre Sonnerat, who first described the animal heard a Malagasy point out the animal and took the word to be its name, it has been suggested that he may have heard the local name endrina, used. Another Malagasy name for the animal is babakoto. Babakoto is most translated as "ancestor" or "father", but several translations are possible. "Koto" is a Malagasy word for "little boy", "baba" is a term for "father", so the word "babakoto" may be translated as "father of a little boy". The father-son dynamic of many of the babakoto origin myths helps to explain the Malagasy name. Along with the diademed sifaka, the indri is the largest lemur still in existence, it can weigh up to 9.0 kg to 9.5 kg It has a head-body length of 64–72 cm and can reach nearly 120 cm with legs extended. The indri is a vertical clinger and leaper and thus holds its body upright when traveling through trees or resting in branches.
It has muscular legs which it uses to propel itself from trunk to trunk. Its large greenish eyes and black face are framed by round, fuzzy ears that some say give it the appearance of a teddy bear. Unlike any other living lemur, the indri has only a rudimentary tail; the silky fur is black with white patches along the limbs, neck and lower back. Different populations of the species show wide variations in color, with some northern populations consisting of or black individuals; the face is bare with pale black skin, it is sometimes fringed with white fur. Due to these color variations, Colin Groves listed two subspecies of the indri in 2005: The dark Indri indri indri from the northern part of its range and the pale Indri indri variegatus from the southern part. Editions of Lemurs of Madagascar by Russell Mittermeier et al. Do not recognize this classification, recent genetic and morphological work suggests the variation in the indri is clinal; the indri practices long-term monogamy. It lives in small groups consisting of their maturing offspring.
In the more fragmented forests of their range, the indri may live in larger groups with several generations. Habitat fragmentation limits the mobility and capacity of these large groups to break into smaller units. Like many other species of lemur, indri live in a female dominant society; the dominant female will displace males to lower branches and poorer feeding grounds, is the one to lead the group during travel. It is common for groups to move 300–700 m daily, with most distance travelled midsummer in search of fruit. Indris sleep in trees about 10–30 m above ground and sleep alone or in pairs, it is common for young female indris adult females, to silently play wrestle anywhere from a few seconds up to 15 minutes. Members of a single group will urinate and defecate jointly at one of their many selected areas of defecation in their territory. Indris reach sexual maturity between the ages of 7 and 9. Females bear offspring every two to three years, with a gestation period around 120–150 days.
The single infant is born in May or June. The mother is the primary caregiver, though the father assists, remaining with his mate and offspring. Infants are born or black and begin to show white coloration between four and six months of age; the infant clings to its mother's belly until it is four or five months old, at which time it is ready to move onto her back. The indri begins to demonstrate independence at eight months, but it will not be independent from its mother until it is at least two years old; the indri is well known for its loud, distinctive songs, which can last from 45 seconds to more than 3 minutes. Song duration and structure varies among and within groups, but most songs have the following three-phase pattern. A "roar sequence" lasting for several seconds will precede the more characteristic vocalizations. All members of the group participate in this roar, but the song proper is dominated by the adult pair, they follow the roar with a "long note sequence", characterized by notes of up to 5 seconds in duration.
After this is the "descending phrase sequence". The wails become progressively lower-pitched, it is common for two or more indri to coordinate the timing of their descending notes to form a
Étienne Geoffroy Saint-Hilaire
Étienne Geoffroy Saint-Hilaire was a French naturalist who established the principle of "unity of composition". He was a colleague of Jean-Baptiste Lamarck and expanded and defended Lamarck's evolutionary theories. Geoffroy's scientific views had a transcendental flavor and were similar to those of German morphologists like Lorenz Oken, he believed in the underlying unity of organismal design, the possibility of the transmutation of species in time, amassing evidence for his claims through research in comparative anatomy and embryology. Geoffroy was born at Étampes, studied at the Collège de Navarre, in Paris, where he studied natural philosophy under M. J. Brisson, he attended the lectures of Daubenton at the College de France and Fourcroy at the Jardin des Plantes. In March 1793 Louis-Jean-Marie Daubenton, through the interest of Bernardin de Saint-Pierre, procured him the office of sub-keeper and assistant demonstrator of the cabinet of natural history, made vacant by the resignation of Bernard Germain Étienne de la Ville, Comte de Lacépède.
By a law passed in June 1793, Geoffroy was appointed one of the twelve professors of the newly constituted Muséum National d'Histoire Naturelle, being assigned the chair of zoology. In the same year he busied himself with the formation of a menagerie at that institution. In 1794, Geoffroy entered into correspondence with Georges Cuvier. Shortly after the appointment of Cuvier as assistant at the Museum d'Histoire Naturelle, Geoffroy received him into his house; the two friends wrote together five memoirs on natural history, one of which, on the classification of mammals, puts forward the idea of the subordination of characters upon which Cuvier based his zoological system. It was in a paper entitled Histoire des Makis, ou singes de Madagascar, written in 1795, that Geoffroy first gave expression to his views on the unity of organic composition, the influence of, perceptible in all his subsequent writings. In 1798, Geoffroy was chosen a member of Napoleon's great scientific expedition to Egypt as part of the natural history and physics section of the Institut d'Égypte.
On the capitulation of Alexandria in August 1801, he took part in resisting the claim made by the British general to the collections of the expedition, declaring that, were that demand persisted in, history would have to record that he had burnt a library in Alexandria. Early in January 1802 Geoffroy returned to Paris, he was elected a member of the French Academy of Sciences in September 1807. In March of the following year Napoleon, who had recognized his national services by the award of the cross of the legion of honor, selected him to visit the museums of Portugal, for the purpose of procuring collections from them, in the face of considerable opposition from the British he was successful in retaining them as a permanent possession for his country. In 1809, the year after his return to France, Geoffroy was made professor of zoology at the faculty of sciences at Paris, from that period he devoted himself more than before to anatomical study. In 1818 he published the first part of his celebrated Philosophie anatomique, the second volume of which, published in 1822, subsequent memoirs account for the formation of monstrosities on the principle of arrest of development, of the attraction of similar parts.
Geoffroy's friend Robert Edmund Grant shared his views on unity of plan and corresponded with him while working on marine invertebrates in the late 1820s in Edinburgh when Grant identified the pancreas in molluscs. When, in 1830, Geoffroy proceeded to apply to the invertebrata his views as to the unity of animal composition, he found a vigorous opponent in Cuvier, his former friend. Geoffroy, a synthesiser, contended, in accordance with his theory of unity of plan in organic composition, that all animals are formed of the same elements, in the same number. With Johann Wolfgang von Goethe he held that there is in nature a law of compensation or balancing of growth, so that if one organ take on an excess of development, it is at the expense of some other part, it was his conviction that, owing to the conditions of life, the same forms had not been perpetuated since the origin of all things, although it was not his belief that existing species are becoming modified. Cuvier, an analytical observer of facts, admitted only the prevalence of laws of co-existence or harmony in animal organs, maintained the absolute invariability of species, which he declared had been created with a regard to the circumstances in which they were placed, each organ contrived with a view to the function it had to fulfil, thus putting, in Geoffroy's considerations, the effect for the cause.
In 1836 he coined the term phocomelia. In July 1840, Geoffroy became blind, some months he had a paralytic attack. From that time his strength failed him, he resigned his chair at the museum in 1841, was succeeded by his son, Isidore Geoffroy Saint