47-537: See " Taxonomy " Dicynodontia is an extinct clade of anomodonts , an extinct type of non-mammalian therapsid . Dicynodonts were herbivores that typically bore a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, typically toothless beak, unique amongst all synapsids . Dicynodonts first appeared in Southern Pangaea during the mid-Permian , ca. 270–260 million years ago, and became globally distributed and
94-717: A phylogenetic tree . In the taxonomical literature, sometimes the Latin form cladus (plural cladi ) is used rather than the English form. Clades are the fundamental unit of cladistics , a modern approach to taxonomy adopted by most biological fields. The common ancestor may be an individual, a population , or a species ( extinct or extant ). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over
141-479: A "ladder", with supposedly more "advanced" organisms at the top. Taxonomists have increasingly worked to make the taxonomic system reflect evolution. When it comes to naming , this principle is not always compatible with the traditional rank-based nomenclature (in which only taxa associated with a rank can be named) because not enough ranks exist to name a long series of nested clades. For these and other reasons, phylogenetic nomenclature has been developed; it
188-623: A clade can be described based on two different reference points, crown age and stem age. The crown age of a clade refers to the age of the most recent common ancestor of all of the species in the clade. The stem age of a clade refers to the time that the ancestral lineage of the clade diverged from its sister clade. A clade's stem age is either the same as or older than its crown age. Ages of clades cannot be directly observed. They are inferred, either from stratigraphy of fossils , or from molecular clock estimates. Viruses , and particularly RNA viruses form clades. These are useful in tracking
235-530: A copy of Lyell's Elements of Geology . He was friendly with William Guybon Atherstone , who was also a keen geologist and fossil collector and who happened to be present at the discovery of Paranthodon africanus Broom at the farm Dassieklip on the Bushmans River , being about half-way between Grahamstown and Port Elizabeth. Bain discovered many fossil remains, including the herbivorous mammal-like reptile dicynodon Oudenodon bainii Owen , which
282-566: A dicynodont, and the name Cryptodontia is no longer used. Thomas Henry Huxley revised Owen's Dicynodontia as an order that included Dicynodon and Oudenodon . Dicynodontia was later ranked as a suborder or infraorder with the larger group Anomodontia, which is classified as an order. The ranking of Dicynodontia has varied in recent studies, with Ivakhnenko (2008) considering it a suborder, Ivanchnenko (2008) considering it an infraorder, and Kurkin (2010) considering it an order. Many higher taxa, including infraorders and families, have been erected as
329-881: A heart attack on 20 October 1864. The Colonial Secretary, the Colonial Treasurer, Charles Davidson Bell , the Surveyor-General and Sir Thomas Maclear , her Majesty's astronomer at the Cape, were among the pallbearers. While resident in Grahamstown he wrote some satirical sketches for local amateur dramatic entertainment and invented the character Caatje Kekelbek or Life Among the Hottentots (1838), also known as Kaatje Kekkelbek (Katie Gossip) who endeared herself forever to South Africans, and held John Philip and other missionaries up to ridicule. Kaatje,
376-407: A large mammal, probably a diprotodontid . With the decline and extinction of the kannemeyerids, there were to be no more dominant large synapsid herbivores until the middle Paleocene epoch (60 Ma) when mammals , distant descendants of cynodonts , began to diversify after the extinction of the non-avian dinosaurs. Dicynodontia was originally named by the English paleontologist Richard Owen . It
423-533: A large variety of ecotypes, including large, medium-sized, and small herbivores and short-limbed mole-like burrowers. Only four lineages are known to have survived the Great Dying ; the first three represented with a single genus each: Myosaurus , Kombuisia , and Lystrosaurus , the latter being the most common and widespread herbivores of the Induan (earliest Triassic ). None of these survived long into
470-716: A means of classifying the large number of dicynodont species. Cluver and King (1983) recognised several main groups within Dicynodontia, including Eodicynodontia (containing only Eodicynodon ), Endothiodontia (containing only Endothiodontidae ), Pristerodontia ( Pristerodontidae , Cryptodontidae , Aulacephalodontidae , Dicynodontidae , Lystrosauridae , and Kannemeyeriidae ), Kingoriamorpha (containing only Kingoriidae ), Diictodontia ( Diictodontidae , Robertiidae , Cistecephalidae , Emydopidae and Myosauridae ), and Venyukoviamorpha . Most of these taxa are no longer considered valid. Kammerer and Angielczyk (2009) suggested that
517-453: A regular correspondent for John Fairbairn's South African Commercial Advertiser . Outspoken, he was sued for libel a number of times by Gerrit Maritz , one of the eventual Voortrekker leaders. He was awarded a special medal in 1832 for 'gratuitously superintending the construction of Van Ryneveld's Pass, Graaff-Reinet'. In 1834 he made another trip to Bechuanaland where he lost his wagons and collection of zoological specimens during an attack by
SECTION 10
#1732765215821564-422: A revised taxonomy based on a concept strongly resembling clades, although the term clade itself would not be coined until 1957 by his grandson, Julian Huxley . German biologist Emil Hans Willi Hennig (1913–1976) is considered to be the founder of cladistics . He proposed a classification system that represented repeated branchings of the family tree, as opposed to the previous systems, which put organisms on
611-462: A skull in 2003. This suggested to indicate that dicynodonts survived into the Cretaceous in southern Gondwana . The dicynodont affinity of these specimens was questioned (including a proposal that they belonged to a baurusuchian crocodyliform by Agnolin et al. in 2010), and in 2019 Knutsen and Oerlemans considered this fossil to be of Plio - Pleistocene age, and reinterpreted it as a fossil of
658-429: A suffix added should be e.g. "dracohortian". A clade is by definition monophyletic , meaning that it contains one ancestor which can be an organism, a population, or a species and all its descendants. The ancestor can be known or unknown; any and all members of a clade can be extant or extinct. The science that tries to reconstruct phylogenetic trees and thus discover clades is called phylogenetics or cladistics ,
705-499: Is also used with a similar meaning in other fields besides biology, such as historical linguistics ; see Cladistics § In disciplines other than biology . The term "clade" was coined in 1957 by the biologist Julian Huxley to refer to the result of cladogenesis , the evolutionary splitting of a parent species into two distinct species, a concept Huxley borrowed from Bernhard Rensch . Many commonly named groups – rodents and insects , for example – are clades because, in each case,
752-405: Is highly specialised, light but strong, with the synapsid temporal openings at the rear of the skull greatly enlarged to accommodate larger jaw muscles. The front of the skull and the lower jaw are generally narrow and, in all but a number of primitive forms, toothless. Instead, the front of the mouth is equipped with a horny beak, as in turtles and ceratopsian dinosaurs . Food was processed by
799-476: Is in turn included in the mammal, vertebrate and animal clades. The idea of a clade did not exist in pre- Darwinian Linnaean taxonomy , which was based by necessity only on internal or external morphological similarities between organisms. Many of the better known animal groups in Linnaeus's original Systema Naturae (mostly vertebrate groups) do represent clades. The phenomenon of convergent evolution
846-631: Is known from the La Belle France cave in South Africa , often conflated with the Dingonek . It may be based on dicynodont fossils. Clade In biological phylogenetics , a clade (from Ancient Greek κλάδος (kládos) 'branch'), also known as a monophyletic group or natural group , is a grouping of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on
893-515: Is responsible for many cases of misleading similarities in the morphology of groups that evolved from different lineages. With the increasing realization in the first half of the 19th century that species had changed and split through the ages, classification increasingly came to be seen as branches on the evolutionary tree of life . The publication of Darwin's theory of evolution in 1859 gave this view increasing weight. In 1876 Thomas Henry Huxley , an early advocate of evolutionary theory, proposed
940-489: Is still controversial. As an example, see the full current classification of Anas platyrhynchos (the mallard duck) with 40 clades from Eukaryota down by following this Wikispecies link and clicking on "Expand". The name of a clade is conventionally a plural, where the singular refers to each member individually. A unique exception is the reptile clade Dracohors , which was made by haplology from Latin "draco" and "cohors", i.e. "the dragon cohort "; its form with
987-912: The Ecca Pass , and displayed engineering talents which gave rise to permanent employment as surveyor of military roads under the Corps of Royal Engineers in 1836. During this period he had a part in building the Fish River Bridge , then the largest bridge in the country. He constructed the Queen's Road from Grahamstown to Fort Beaufort . Appointed Engineering Inspector by the Cape Roads Board in 1845 he began construction at Michell's Pass near Ceres in 1848, subsequently followed on completion by Bain's Kloof Pass near Wellington in 1853. During 1853 he met with Russian novelist I. A. Goncharov, while
SECTION 20
#17327652158211034-704: The Matabele , caused by his Griqua guides' stealing some of the King's cattle. During the Cape Frontier Wars in 1833–1834 he served as captain of the Beaufort Levies raised for the defence of the frontier. He tried his hand at farming in the newly annexed Queen Adelaide Province, but lost the farm when the land was returned to the Xhosa in 1836. Later he was engaged to construct a military road through
1081-526: The ilium are large and strong. The tail is short. Pentasauropus dicynodont tracks suggest that dicynodonts had fleshy pads on their feet. Mummified skin from specimens of Lystrosaurus in South Africa have numerous raised bumps. Dicynodonts have long been suspected of being warm-blooded animals. Their bones are highly vascularised and possess Haversian canals , and their bodily proportions are conducive to heat preservation. In young specimens,
1128-473: The British Museum . By this time, many more dicynodonts had been described. In 1859, another important species called Ptychognathus declivis was named from South Africa. In the same year, Owen named the group Dicynodontia. In his Descriptive and Illustrated Catalogue , Owen honored Bain by erecting Bidentalia as a replacement name for his Dicynodontia. The name Bidentalia quickly fell out of use in
1175-540: The English paleontologist Richard Owen named two species of dicynodonts from South Africa: Dicynodon lacerticeps and Dicynodon bainii . Since Bain was preoccupied with the Corps of Royal Engineers, he wanted Owen to describe his fossils more extensively. Owen did not publish a description until 1876 in his Descriptive and Illustrated Catalogue of the Fossil Reptilia of South Africa in the Collection of
1222-669: The Government on the copper mines there. He was granted sick leave to visit England for a second time in 1864, where he was entertained by Sir Richard Owen of the British Museum and Sir Roderick Murchison of the Royal Geographical Society , and was made an honorary member of the Athenaeum Club . His health at this time deteriorated markedly and he returned to South Africa; he died in Cape Town following
1269-755: The Hottentot girl, uses Hottentot-Afrikaans in the spoken parts, and sings in Afrikaans-English. She comes on stage playing a Jew's-harp: Bain's journals were published by the Van Riebeeck Society in 1949. A memorial plaque was unveiled at the summit of Bain's Kloof Pass on 14 September 1953, and a memorial to him was erected at the top of the Ecca Pass on the Queen's Road on 7 September 1964. Bain built eight major mountain roads and passes during his career. His son Thomas Charles John Bain
1316-510: The Permian extinction. A 2024 paper posited that rock art of a superficially walrus-like imaginary creature with downcurved tusks created by the San people of South Africa prior to 1835 may have been partly inspired by fossil dicynodont skulls which erode out of rocks in the area. Dicynodonts have been known to science since the mid-1800s. The South African geologist Andrew Geddes Bain gave
1363-864: The Triassic. The fourth group was the Kannemeyeriiformes , the only dicynodonts who diversified during the Triassic. These stocky, pig- to ox-sized animals were the most abundant herbivores worldwide from the Olenekian to the Ladinian age. By the Carnian they had been supplanted by traversodont cynodonts and rhynchosaur reptiles. During the Norian (middle of the Late Triassic), perhaps due to increasing aridity, they drastically declined, and
1410-769: The bones are so highly vascularised that they exhibit higher channel densities than most other therapsids. Yet, studies on Late Triassic dicynodont coprolites paradoxically showcase digestive patterns more typical of animals with slow metabolisms. More recently, the discovery of hair remnants in Permian coprolites possibly vindicates the status of dicynodonts as endothermic animals. As these coprolites come from carnivorous species and digested dicynodont bones are abundant, it has been suggested that at least some of these hair remnants come from dicynodont prey. A new study using chemical analysis seemed to suggest that cynodonts and dicynodonts both developed warm blood independently before
1457-699: The business of a saddler. In 1825 he accompanied John Burner Biddulph on a trading expedition to Kuruman , the mission outpost on the edge of the Kalahari and home of Dr. Robert Moffat (father-in-law of David Livingstone ). They explored further north and reached Dithubaruba in Bechuanaland , becoming the first recorded Europeans to return safely from so far north. In 1829 they trekked to the vicinity of present-day Kokstad . They were forced to return by hordes of Bantu fleeing Dingaan . During these journeys he discovered his talent for drawing and writing and became
Dicynodontia - Misplaced Pages Continue
1504-565: The dominant herbivorous animals in the Late Permian , ca. 260–252 Mya. They were devastated by the end-Permian Extinction that wiped out most other therapsids ca. 252 Mya. They rebounded during the Triassic but died out towards the end of that period. They were the most successful and diverse of the non-mammalian therapsids, with over 70 genera known, varying from rat-sized burrowers to elephant-sized browsers . The dicynodont skull
1551-480: The first comprehensive geological map of South Africa, a work of great merit, which was published by the Geological Society of London in 1856. Sir Roderick Murchison and Sir Henry de la Beche , prominent geologists of the time, both recommended Bain's appointment as Cape Geological Surveyor in 1852, but since no funds were available, nothing came of it. Bain went to Namaqualand in 1854 and reported to
1598-597: The first description of dicynodonts in 1845. At the time, Bain was a supervisor for the construction of military roads under the Corps of Royal Engineers and had found many reptilian fossils during his surveys of South Africa. Bain described these fossils in an 1845 letter published in Transactions of the Geological Society of London , calling them "bidentals" for their two prominent tusks. In that same year,
1645-546: The following years, replaced by popularity of Owen's Dicynodontia. Dicynodonts first appeared during the Middle Permian in the Southern Hemisphere, with South Africa being the centre of their known diversity, and underwent a rapid evolutionary radiation , becoming globally distributed and amongst the most successful and abundant land vertebrates during the Late Permian . During this time, they included
1692-546: The group consists of a common ancestor with all its descendant branches. Rodents, for example, are a branch of mammals that split off after the end of the period when the clade Dinosauria stopped being the dominant terrestrial vertebrates 66 million years ago. The original population and all its descendants are a clade. The rodent clade corresponds to the order Rodentia, and insects to the class Insecta. These clades include smaller clades, such as chipmunk or ant , each of which consists of even smaller clades. The clade "rodent"
1739-590: The last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic . Some of the relationships between organisms that the molecular biology arm of cladistics has revealed include that fungi are closer relatives to animals than they are to plants, archaea are now considered different from bacteria , and multicellular organisms may have evolved from archaea. The term "clade"
1786-518: The latter term coined by Ernst Mayr (1965), derived from "clade". The results of phylogenetic/cladistic analyses are tree-shaped diagrams called cladograms ; they, and all their branches, are phylogenetic hypotheses. Three methods of defining clades are featured in phylogenetic nomenclature : node-, stem-, and apomorphy-based (see Phylogenetic nomenclature§Phylogenetic definitions of clade names for detailed definitions). The relationship between clades can be described in several ways: The age of
1833-632: The latter was conducting a journey to Japan on frigate Pallada. He was the first man to attempt to build a road across the Limiet Mountains into the interior for which feat he was presented with table silver and a candelabrum by grateful colonists. Returning to the Eastern Cape in 1854, he built numerous roads and passes including the Katberg Pass near Fort Beaufort. This occupation created an interest in geology, inspired in 1837 by
1880-402: The presence of tusks has been suggested to be sexually dimorphic . Some dicynodonts such as Stahleckeria lacked true tusks and instead bore tusk-like extensions on the side of the beak. The body is short, strong and barrel-shaped, with strong limbs. In large genera (such as Dinodontosaurus ) the hindlimbs were held erect, but the forelimbs bent at the elbow. Both the pectoral girdle and
1927-468: The problematic taxonomy and nomenclature of Dicynodontia and other groups results from the large number of conflicting studies and the tendency for invalid names to be mistakenly established. Below is a cladogram modified from Angielczyk et al. (2021): Nyaphulia Eodicynodon Colobodectes Lanthanostegus Pylaecephalidae Eumantellidae Brachyprosopus Endothiodontia Emydopoidea Bidentalia A horned serpent cave art
Dicynodontia - Misplaced Pages Continue
1974-476: The retraction of the lower jaw when the mouth closed, producing a powerful shearing action, which would have enabled dicynodonts to cope with tough plant material. Dicynodonts typically had a pair of enlarged maxillary caniniform teeth, analogous to the tusks present in some living mammals. In the earliest genera, they were merely enlarged teeth, but in later forms they independently evolved into ever-growing teeth like mammal tusks multiple times. In some dicynodonts,
2021-546: The role of large herbivores was taken over by sauropodomorph dinosaurs. Fossils of an Asian elephant -sized dicynodont Lisowicia bojani discovered in Poland indicate that dicynodonts survived at least until the late Norian or earliest Rhaetian (latest Triassic); this animal was also the largest known dicynodont species. Six fragments of fossil bone discovered in Queensland , Australia, were interpreted as remains of
2068-678: The spread of viral infections . HIV , for example, has clades called subtypes, which vary in geographical prevalence. HIV subtype (clade) B, for example is predominant in Europe, the Americas and Japan, whereas subtype A is more common in east Africa. Andrew Geddes Bain Andrew Geddes Bain (baptised 11 June 1797 – 20 October 1864), was a Cape Colony geologist, road engineer, palaeontologist and explorer. The only child of Alexander Bain and Jean Geddes, both of whom died when Bain
2115-419: Was erected as a family of the order Anomodontia and included the genera Dicynodon and Ptychognathus . Other groups of Anomodontia included Gnathodontia , which included Rhynchosaurus (now known to be an archosauromorph ) and Cryptodontia , which included Oudenodon . Cryptodonts were distinguished from dicynodonts from their absence of tusks. Although it lacks tusks, Oudenodon is now classified as
2162-540: Was excavated from the Karoo Beds on the farm Mildenhall south of Fort Beaufort and described in the literature by Sir Richard Owen . Among the specimens sent to Owen was the so-called Blinkwater monster, Pareiasaurus serridens as well as a variety of mammal-like reptiles. He was awarded £200 by the British government in 1845 for his researches. Devoting his spare time to geological studies, Bain prepared in 1852
2209-626: Was still a young boy, Bain was baptised 11 June 1797 in Thurso , Scotland. He was raised by an aunt who lived near Edinburgh . Here he received a classical education, but no vocational training. In 1816 he emigrated to Cape Town accompanied by his uncle Lieutenant Colonel William Geddes of the 83rd Regiment, who was stationed in the Cape. He married Maria Elizabeth von Backstrom on 16 November 1818 and had 3 sons and 7 daughters. In 1822 he bought property in Graaff Reinet and carried on for some years
#820179