An omnivore is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein and fiber, metabolize the nutrients and energy of the sources absorbed, they have the ability to incorporate food sources such as algae and bacteria into their diet. Omnivores come from diverse backgrounds that independently evolved sophisticated consumption capabilities. For instance, dogs evolved from carnivorous organisms while pigs evolved from herbivorous organisms. What this means is that physical characteristics are not reliable indicators of whether an animal has the ability to obtain energy and nutrients from both plant and animal matter. Owing to the wide range of unrelated organisms independently evolving the capability to obtain energy and nutrients from both plant and animal materials, no generalizations about the anatomical features of all omnivores can realistically be made; the variety of different animals that are classified as omnivores can be placed into further categories depending on their feeding behaviors.
Frugivores include maned orangutans. All of these animals are omnivores, yet still fall into special niches in terms of feeding behavior and preferred foods. Being omnivores gives these animals more food security in stressful times or makes possible living in less consistent environments; the word omnivore derives from the Latin omnis, vora, from vorare, having been coined by the French and adopted by the English in the 1800s. Traditionally the definition for omnivory was behavioral by means of "including both animal and vegetable tissue in the diet." In more recent times, with the advent of advanced technological capabilities in fields like gastroenterology, biologists have formulated a standardized variation of omnivore used for labeling a species' actual ability to obtain energy and nutrients from materials. This has subsequently conditioned two context specific definitions. Behavioral: This definition is used to specify if a species or individual is consuming both plant and animal materials.
Physiological: This definition is used in academia to specify species that have the capability to obtain energy and nutrients from both plant and animal matter. The taxonomic utility of omnivore's traditional and behavioral definition is limited, since the diet and phylogeny of one omnivorous species might be different from that of another: for instance, an omnivorous pig digging for roots and scavenging for fruit and carrion is taxonomically and ecologically quite distinct from an omnivorous chameleon that eats leaves and insects; the term "omnivory" is not always comprehensive because it does not deal with mineral foods such as salt licks and the consumption of plant and animal material for medical purposes which would not otherwise be consumed within non-omnivores. Though Carnivora is a taxon for species classification, no such equivalent exists for omnivores, as omnivores are widespread across multiple taxonomic clades; the Carnivora order does not include all carnivorous species, not all species within the Carnivora taxon are carnivorous.
It is common to find physiological carnivores consuming materials from plants or physiological herbivores consuming material from animals, e.g. felines eating grass and deer eating birds. From a behavioral aspect, this would make them omnivores, but from the physiological standpoint, this may be due to zoopharmacognosy. Physiologically, animals must be able to obtain both energy and nutrients from plant and animal materials to be considered omnivorous. Thus, such animals are still able to be classified as carnivores and herbivores when they are just obtaining nutrients from materials originating from sources that do not complement their classification. For instance, it is well documented that animals such as giraffes and cattle will gnaw on bones, preferably dry bones, for particular minerals and nutrients. Felines, which are regarded as obligate carnivores eat grass to regurgitate indigestibles, aid with hemoglobin production, as a laxative, it is found that animals classified as carnivorous may deliberately eat plant material.
For example, in 2013, it was considered that American alligators may be physiologically omnivorous once investigations had been conducted on why they eat fruits. It was suggested that alligators ate fruits both accidentally but deliberately."Life-history omnivores" is a specialized classification given to organisms that change their eating habits during their life cycle. Some species, such as grazing waterfowl like geese, are known to eat animal tissue at one stage of their lives, but plant matter at another; the same is true for many insects, such as beetles in the family Meloidae, which begin by eating animal tissue as larvae, but change to eating plant matter after they mature. Many mosquito species in early life eat plants or assorted detritus, but as they mature, males continue to eat plant matter and nectar whereas the females eat blood to reproduce effectively. Although cases exist of herbivores eating meat and carnivores eating plant matter, the classification "omnivore" re
Clevosaurus is an extinct genus of rhynchocephalian reptile from the Triassic and the Jurassic periods of Nova Scotia, Great Britain, Yunnan. Clevosaurus was similar to the modern tuatara in every way. Clevosaurus was smaller than the modern tuatara. Clevosaurus ate plants as well as insects, as suggested by the form of the teeth. Fossils of Clevosaurus, as well as other sphenodontians, early mammals and dinosaurs have been found in ancient cave systems of Great Britain. Clevosaurus is now believed to have had Pangaean distribution; some fossils from South America found in 2006 represent a new species of Clevosaurus. A new species has been named Clevosaurus sectumsemper after the spell from Harry Potter. Below is a cladogram of the relationships within Clevosauridae based on the phylogenetic analysis of Hsiou et al.: "Clevosaurus" latidens was recovered outside of Clevosauridae, as the sister taxon of Opisthodontia. It was subsequently assigned to a new genus, Fraserosphenodon, in 2018. Paleofile Gill PG, Säilä LK, Corfe IJ, Challands TJ, Williams M, Clemens WA.
The fauna and palaeoenvironment of St. Brides Island: Evidence from the lower Jurassic fissure fills of South Wales. In Barrett PM, Evans SE. Ninth international symposium on Mesozoic terrestrial ecosystems and biota. Pp 48−51. London: Natural History Museum. Jones MEH The Early Jurassic clevosaurs from China. Natl Mus Nat Hist Sci Bull, 37:548–562. Jones MEH. Dentary tooth shape in its fossil relatives. In Koppe T, Meyer G, Alt KW. Interdisciplinary Dental Morphology, Frontiers of Oral Biology. Greifswald, Germany. 9–15
Chewing or mastication is the process by which food is crushed and ground by teeth. It is the first step of digestion, it increases the surface area of foods to allow a more efficient break down by enzymes. During the mastication process, the food is positioned by the cheek and tongue between the teeth for grinding; the muscles of mastication move the jaws to bring the teeth into intermittent contact occluding and opening. As chewing continues, the food is made softer and warmer, the enzymes in saliva begin to break down carbohydrates in the food. After chewing, the food is swallowed, it enters the esophagus and via peristalsis continues on to the stomach, where the next step of digestion occurs. Premastication is sometimes performed by human parents for infants who are unable to do so for themselves; the food is masticated in the mouth of the parent into a bolus and transferred to the infant for consumption. Cattle and some other animals, called ruminants, chew food more than once to extract more nutrients.
After the first round of chewing, this food is called cud. Chewing is an unconscious act, but can be mediated by higher conscious input; the motor program for mastication is a hypothesized central nervous system function by which the complex patterns governing mastication are created and controlled. It is thought that feedback from proprioceptive nerves in teeth and the temporomandibular joints govern the creation of neural pathways, which in turn determine duration and force of individual muscle activation; this motor program continuously adapts to changes in food occlusion. This adaptation is a learned skill that may sometimes require relearning to adapt to loss of teeth or to dental appliances such as dentures, it is thought that conscious mediation is important in the limitation of parafunctional habits as most the motor program can be excessively engaged during periods of sleep and times of stress. It is theorized that excessive input to the motor program from myofascial pain or occlusal imbalance can contribute to parafunctional habits.
A study found that unchewed meat and vegetables were not digested, while tallow, fish and grains did not need to be chewed. Chewing stimulates saliva production and increases sensory perception of the food being eaten, controlling when the food is swallowed. Avoiding chewing, by choice or due to medical reasons as tooth loss, is known as a soft diet; such a diet may lead to inadequate nutrition due to a reduction in vegetable intake. Chewing stimulates the hippocampus and is necessary to maintain its normal function. Chewing is an adaptation for mammalian herbivory. Carnivores chew little or swallow their food whole or in chunks; this act of gulping food without chewing has inspired the English idiom "wolfing it down". Ornithopods, a group of dinosaurs including the Hadrosaurids, developed teeth analogous to mammalian molars and incisors during the Cretaceous period; this may have given them the advantage needed to usurp the formidable sauropods, who depended on gastroliths for grinding food, from their ecological niches.
They became some of the most successful animals on the planet until the Cretaceous–Paleogene extinction event wiped them out. The process of chewing has, by analogy, been applied to machinery; the U. S. Forest Service uses a machine called a masticator to "chew" through brush and timber in order to clear firelines in advance of a wildfire. Biting Gnathology Muscles of mastication Horace Fletcher Chewing Gum MeSH A02.633.567.600
Hyaenodontidae is a family of extinct predatory mammals, is the type family of the extinct mammalian order Hyaenodonta. Hyaenodontids were important mammalian predators that arose during the late Paleocene and persisted well into the Miocene, they were more widespread and successful than the oxyaenids, the other clade considered part of Creodonta. Hyaenodontids of Hyaenodontidae are characterized by long skulls, slender jaws, slim bodies, a plantigrade stance, they ranged in size from 30 to 140 cm at the shoulder. While Hyaenodon gigas, the largest Hyaenodon species, was as much as 1.4 m high at the shoulder, 10 feet long and weighed about 500 kg, most were in the 5–15 kg range, equivalent to a mid-sized dog. The anatomy of their skulls show that they had a acute sense of smell, while their teeth were adapted for shearing, rather than crushing; because of their size range, it is probable that different species hunted in different ways, which allowed them to fill many different predatory niches.
Smaller ones would hunt in packs during the night like wolves, bigger, fiercer ones would hunt alone during the daylight, using their sheer size and their mighty jaws as their principal weapon. The carnassials in a hyaenodontid are the second upper and third lower molars. However, some hyaenodontids possessed as many as three sequential pairs of carnassials or carnassial-like molar teeth in their jaws. Hyaenodontids lacked post-carnassial crushing molar teeth, thus lacked dental versatility for processing any foods other than meat. Hyaenodontids are unusual in regards to their tooth replacement. Studies on Hyaenodon show that juveniles took 3–4 years in the last stage of tooth eruption, implying a long adolescent phase. In North American forms, the first upper premolar erupts before the first upper molar, while European forms show an earlier eruption of the first upper molar. At least one hyaenodontid lineage, was specialised for aquatic, otter-like habits. Having evolved in Africa during the Paleocene, hyaenodontids soon after spread into India and Europe, implying close biogeographical connections between these areas.
Afterwards they dispersed into Asia from either Europe or India, North America. They were important hypercarnivores in Eurasia and North America during the Oligocene, but declined, with the entire family becoming extinct by the close of the Oligocene. Only four genera, its sister genera Hyainailouros and Dissopsalis, the youngest species of Hyaenodon, H. weilini, survived into the Miocene, of which, only Dissopsalis survived long enough to go extinct at the close of the Miocene. Traditionally this has been attributed to competition with carnivorans, but no formal examination of the correlation between the decline of hyaenodontids and the expansion of carnivorans has been reccorded, the latter may have moved into vacant niches after the extinction of hyaenodontid species. Hyaenodontids were classified in Creodonta, alongside other predatory mammal groups like oxyaenids; some researchers consider the clade a wastebasket taxon containing two unrelated clades assumed to be related to or ancestral to Carnivora.
However, a recent phylogenetic analysis of Paleogene mammals supports the monophyly of Creodonta, places them in Ferae, close to Pholidota. ORDER CREODONTA creodonts Family HyaenodontidaeGenus Ischnognathus Genus Tinerhodon Subfamily Arfiinae Genus Arfia Subfamily Hyaenodontinae Genus Hyaenodon Genus Neoparapterodon Genus Propterodon Subfamily Indohyaenodontinae Genus Indohyaenodon Genus Kyawdawia Genus Paratritemnodon Genus Yarshea Subfamily Limnocyoninae Genus Iridodon Genus Limnocyon Genus Oxyaenodon Genus Prolaena Genus Prolimnocyon Genus Thereutherium Genus Thinocyon Subfamily Proviverrinae Genus Alienetherium Genus Allopterodon Genus Consobrinus Genus Cynohyaenodon Genus Eurotherium Genus Leonhardtina Genus Lesmesodon Genus Matthodon Genus Minimovellentodon Genus Morlodon Genus Orienspterodon Genus Oxyaenoides Genus Paenoxyaenoides Genus Paracynohyaenodon Genus Paravagula Genus Praecodens Genus Preregidens Genus Prodissopsalis Genus Proviverra Genus Quercitherium Subfamily SinopinaeGenus Acarictis Genus Galecyon Genus Gazinocyon Genus Prototomus Genus Proviverroides Genus Pyrocyon Genus Sinopa Genus TritemnodonThe Machaeroidinae are sometimes placed here, e.g. by Egi, 2001.
Hyainailourinae was elevated to family rank in 2015
Gobiconodon is an extinct genus of carnivorous mammal from the early Cretaceous. It measured 18 -- 20 inches, it was one of the largest mammals known from the Mesozoic. Like other gobiconodontids, it possesses several speciations towards carnivory, such as shearing molar teeth, large canine-like incisors and powerful jaw and forelimb musculature, indicating that it fed on vertebrate prey. Like the larger Repenomamus there might be some evidence of scavenging
Mesonychia is an extinct taxon of small- to large-sized carnivorous ungulates related to the cetartiodactyls. Mesonychids first appeared in the early Paleocene, went into a sharp decline at the end of the Eocene, died out when the last genus, became extinct in the early Oligocene, they resembled wolves. Early mesonychids walked on the flats of their feet, while ones walked on their toes; these mesonychids had hooves, one on each toe, with four toes on each foot. Mesonychids originated in China, where the most primitive mesonychid, Yangtanglestes, is known from the early Paleocene, they were most diverse in Asia, where they occur in all major Paleocene faunas. Since other carnivores, such as the creodonts and condylarths, were either rare or absent in these animal communities, mesonychids most dominated the large predator niche in the Paleocene of Eastern Asia. One genus, had spread to Europe and North America by the early Paleocene. Dissacus was a jackal-sized carnivore, found all over the Northern Hemisphere, but its daughter genus, from the early to middle Paleocene of New Mexico, was far larger, growing to the size of a bear.
Species of the genus, entered North America by the earliest Eocene, where they evolved into huge species surpassing Ankalagon in size. Mesonychids in North America were by far the largest predatory mammals during the early Paleocene to middle Eocene. In life, mesonychids are thought to superficially resemble to canids. Early mesonychids had five digits on their feet, which rested flat on the ground during walking, but mesonychids had four digits that ended in tiny hooves on all of their toes and were well adapted to running. Like running members of the even-toed ungulates, mesonychids walked on their digits; these "wolves on hooves" were one of the more important predator groups in the late Paleocene and Eocene ecosystems of Europe and North America. Mesonychid dentition consisted of molars modified to generate vertical shear, thin blade-like lower molars, carnassial notches, but no true carnassials; the molars were laterally compressed and blunt, were used for shearing meat or crushing bones.
Many species are suspected of being fish-eaters, the largest species are considered to have been scavengers. Mesonychians were long considered to be creodonts, but have now been removed from that order and placed in three families, either within their own order, Mesonychia, or within the order Condylarthra as part of the cohort or superorder Laurasiatheria. Nearly all mesonychids are, on average, larger than most of the Paleocene and Eocene creodonts and miacoid carnivorans; the order is sometimes referred to by its older name "Acreodi". Technically speaking, the term "mesonychid" refers only to the members of the family Mesonychidae, such as the species of the genus Mesonyx. However, as the order is renamed for Mesonyx, the term "mesonychid" is now used to refer to members of the entire order Mesonychia and the species of other families within it. A recent study found mesonychians to be basal euungulates most related to the "arctocyonids" Mimotricentes and Chriacus. "Triisodontidae" may be paraphyletic.
Mesonychids possess unusual triangular molar teeth that are similar to those of Cetacea those of the archaeocetes, as well as having similar skull anatomies and other morphologic traits. For this reason, scientists had long believed that mesonychids were the direct ancestor of Cetacea, but the discovery of well-preserved hind limbs of archaic cetaceans, as well as more recent phylogenetic analyses now indicate cetaceans are more related to hippopotamids and other artiodactyls than they are to mesonychids, this result is consistent with many molecular studies. Most paleontologists now doubt that whales are descended from mesonychids, instead suggest that they are either descended from, or share a common ancestor with, the anthracotheres, the semiaquatic ancestors of hippos. However, the close grouping of whales with hippopotami in cladistic analyses only surfaces following the deletion of Andrewsarchus, included within the mesonychids. One possible conclusion is that Andrewsarchus is not a mesonychid, but rather allied with hippopotamids.
The current uncertainty may, in part, reflect the fragmentary nature of the remains of some crucial fossil taxa, such as Andrewsarchus. Paleocene Mammals of the World: Carnivores and Carnivorous Ungulates Mesonychids in Cryptozoology
The thylacine ( THY-lə-seen, or THY-lə-syne, also. The last known live animal was captured in 1933 in Tasmania, it is known as the Tasmanian tiger because of its striped lower back, or the Tasmanian wolf because of its canid-like characteristics. It was native to Tasmania, New Guinea, the Australian mainland; the thylacine was shy and nocturnal, with the general appearance of a medium-to-large-size dog, except for its stiff tail and abdominal pouch similar to a kangaroo, dark transverse stripes that radiated from the top of its back, reminiscent of a tiger. The thylacine was a formidable apex predator, though how large its prey animals were is disputed; because of convergent evolution it displayed a form and adaptations similar to the tiger and wolf of the Northern Hemisphere though not related. Its closest living relative is either the numbat; the thylacine was one of only two marsupials to have a pouch in both sexes: the other is the water opossum. The pouch of the male thylacine served as a protective sheath covering the external reproductive organs.
The thylacine had become rare or extinct on the Australian mainland before British settlement of the continent, but it survived on the island of Tasmania along with several other endemic species, including the Tasmanian devil. Intensive hunting encouraged by bounties is blamed for its extinction, but other contributing factors may have been disease, the introduction of dogs, human encroachment into its habitat. Numerous examples of thylacine engravings and rock art have been found dating back to at least 1000 BC. Petroglyph images of the thylacine can be found at the Dampier Rock Art Precinct on the Burrup Peninsula in Western Australia. By the time the first European explorers arrived, the animal was extinct in mainland Australia and rare in Tasmania. Europeans may have encountered it in Tasmania as far back as 1642 when Abel Tasman first arrived in Tasmania, his shore party reported seeing the footprints of "wild beasts having claws like a Tyger". Marc-Joseph Marion du Fresne, arriving with the Mascarin in 1772, reported seeing a "tiger cat".
Positive identification of the thylacine as the animal encountered cannot be made from this report since the tiger quoll is described. The first definitive encounter was by French explorers on 13 May 1792, as noted by the naturalist Jacques Labillardière, in his journal from the expedition led by D'Entrecasteaux. In 1805 William Paterson, the Lieutenant Governor of Tasmania, sent a detailed description for publication in the Sydney Gazette, he sent a description of the Thylacine in a letter to Joseph Banks dated 30 March 1805. The first detailed scientific description was made by Tasmania's Deputy Surveyor-General, George Harris in 1808, five years after first European settlement of the island. Harris placed the thylacine in the genus Didelphis, created by Linnaeus for the American opossums, describing it as Didelphis cynocephala, the "dog-headed opossum". Recognition that the Australian marsupials were fundamentally different from the known mammal genera led to the establishment of the modern classification scheme, in 1796, Geoffroy Saint-Hilaire created the genus Dasyurus where he placed the thylacine in 1810.
To resolve the mixture of Greek and Latin nomenclature, the species name was altered to cynocephalus. In 1824, it was separated out into Thylacinus, by Temminck; the common name derives directly from the genus name from the Greek θύλακος, meaning "pouch" or "sack". The modern thylacine appeared about 4 million years ago. Species of the family Thylacinidae date back to the beginning of the Miocene. Dickson's thylacine is the oldest of the seven discovered fossil species, dating back to 23 million years ago; this thylacinid was much smaller than its more recent relatives. The largest species, the powerful thylacine which grew to the size of a wolf, was the only species to survive into the late Miocene. In late Pleistocene and early Holocene times, the modern thylacine was widespread throughout Australia and New Guinea. An example of convergent evolution, the thylacine showed many similarities to the members of the dog family, Canidae, of the Northern Hemisphere: sharp teeth, powerful jaws, raised heels and the same general body form.
Since the thylacine filled the same ecological niche in Australia as the dog family did elsewhere, it developed many of the same features. Despite this, as a marsupial it is unrelated to any of the Northern Hemisphere placental mammal predators, they are easy to tell from a true dog because of the stripes on the back but the skeleton is harder to distinguish. Zoology students at Oxford had to identify 100 zoological specimens as part of the final exam. Word soon got around that, if a'dog' skull was given, it was safe to identify it as Thylacinus on the grounds that anything as obvious as a dog skull had to be a catch. One year the examiners, to their credit, double bluffed and put in a real dog skull; the easiest way to tell the difference is by the two prominent holes in the palate bone, which are characteristic of marsupials generally. The thylacine is a basal member of the Dasyuromorphia along with numbats, dunnarts and quolls; the cladogram follows: Descriptions of the thylacine come from preserved specimens, fossil reco