Dicynodontia Fossil range: Middle Permian to Late Triassic (new finds in the Cretaceous)
Lystrosaurus, one of few species of dicynodonts that survived the Permian-Triassic extinction event.
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Synapsida Order: Therapsida Suborder: Anomodontia Infraorder: Dicynodontia Owen, 1859
Clades & Genera
see "Taxonomy" The Permian is a geologic period that extends from about 299. ... The Late Triassic (also known as Upper Triassic, or Keuper) is the third and final of three epochs of the Triassic period. ... The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... Image File history File links Lystrosaurus. ... Species Lystrosaurus curvatus Lystrosaurus declivus Lystrosaurus mccaigi Lystrosaurus murrayi Lystrosaurus oviceps Lystrosaurus platyceps Lystrosaurus (meaning shovel reptile, pronounced list-row-sore-uss) was a genus of Early Triassic Period therapsids, which lived approximately 250 million years ago in what is now Antarctica, India and South Africa. ... The Permian-Triassic (P-T or PT) extinction event, sometimes informally called the Great Dying, was an extinction event that occurred approximately 251 million years ago (mya), forming the boundary between the Permian and Triassic geologic periods. ... Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... Digimon, the only known animals. ... Template:Tax more Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... Orders & Suborders Order Pelycosauria * Suborder Caseasauria Suborder Eupelycosauria * Order Therapsida * Suborder Biarmosuchia Suborder Dinocephalia Suborder Anomodontia Suborder Gorgonopsia Suborder Therocephalia Suborder Cynodontia * For complete phylogeny, see text. ... Suborders Biarmosuchia Dinocephalia Eotheriodontia Anomodontia Gorgonopsia Therocephalia Cynodontia Therapsids, previously known as the mammal-like reptiles, are an order of synapsids. ... Groups Anomocephalus Patranomodon Venyukoviidae Dromasauria Dicynodontia The Anomodontia are one of the three major groups of Therapsids. ... Sir Richard Owen KCB (July 20, 1804–December 18, 1892) was an English biologist, comparative anatomist and palaeontologist. ...

The Dicynodontia are a taxon of Therapsids or mammal-like reptiles. Dicynodonts were small to large herbivorous animals with two tusks, hence their name, which means 'two dog tooth'. They are also the most successful and diverse of the therapsids, with over 70 genera known, varying from rat- to ox-sized. A taxon (plural taxa), or taxonomic unit, is a grouping of organisms (named or unnamed). ... Groups Biarmosuchia Dinocephalia Anomodontia Theriodontia    Cynodontia       (...mammals) Therapsids, previously known as the mammal-like reptiles, are a group of synapsids. ... Mammal-like reptiles is a term used to describe the prehistoric animals that appear to be the reptilian ancestors of mammals. ... A deer and two fawns feeding on some foliage A herbivore is often defined as any organism that eats only plants[1]. By that definition, many fungi, some bacteria, many animals, about 1% of flowering plants and some protists can be considered herbivores. ... For other uses of the word, please see Genus (disambiguation). ...

Characteristics

The Dicynodont skull is highly specialised; light but strong, with the synapsid temporal openings at the rear of the skull are greatly enlarged, to accommodate larger jaw muscles. Groups Caseasauria Eupelycosauria    Sphenacodontia       Therapsida          (...mammals) Synapsids (fused arch), formerly known as mammal-like reptiles, are a group of amniotes (reptiles and all their ancestors) that developed one hole in their skull (temporal fenestra) behind each eye, about 320 million years ago (Ma) during the late Carboniferous. ...

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 through retraction of the lower jaw when the mouth closed, producing a powerful shearing action (Crompton and Hotton 1967), which would have enabled dicynodonts to cope with tough plant material. It has been suggested that temporal fenestra be merged into this article or section. ... An order of Reptiles, called the Crown Group. Its distinctive characteristic is that part of its vertebrae, ribs, and sternum unite with its dermal plates so as to form a firm shell. ... The Ceratopsia are a group of omnivorous and herbivorous, beaked dinosaurs which thrived in North America and Asia during the Cretaceous. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ...

Many genera also have a pair of tusks, which it is thought may have been an example of sexual dimorphism (Colbert 1969 p.137) Female (left) and male Common Pheasant, illustrating the dramatic difference in both color and size between the sexes Sexual dimorphism is the systematic difference in form between individuals of different sex in the same species. ...

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 the ilium are large and strong. The tail is short. The pectoral girdle is the set of bones which connect the upper limb to the axial skeleton on each side. ... The term Illion, Ilium has several meanings, including in legends, in anatomy, and in the arts: Ilion or Ilium is an alternative name for the legendary city of Troy. ...

Evolutionary History

Eodicynodon, a primitive dicynodont from the middle Permian of South Africa

Dicynodonts first appear during Middle Permian, and underwent a rapid evolutionary radiation, becoming the most successful and abundant land vertebrates of the Late Permian. During this time they including a large variety of ecotypes, including large, medium-sized, and small herbivores and short-limbed mole-like burrowers. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... The Permian is a geologic period that extends from about 299. ... Guadalupian - the second of the three epoches of the Permian, it lasted from about 270 to 260 million years ago. ... This article is in need of attention from an expert on the subject. ... Lopingian is the third of the three epoches of the Permian. ...

Only two families survived the end Permian extinction, one of which, the Lystrosauridae, were the most common and widespread herbivores of the Induan (earliest Triassic). These medium-sized animals evolved into and were replaced by the Kannemeyeridae, stocky, pig- to ox-sized animals that 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), when - perhaps due to increasing aridity - they drastically declined, and the role of large herbivore was taken over by sauropodomorph dinosaurs. The Permian-Triassic (P-T or PT) extinction event, sometimes informally called the Great Dying, was an extinction event that occurred approximately 251 million years ago (mya), forming the boundary between the Permian and Triassic geologic periods. ... Species Lystrosaurus curvatus Lystrosaurus declivus Lystrosaurus mccaigi Lystrosaurus murrayi Lystrosaurus oviceps Lystrosaurus platyceps Lystrosaurus (meaning shovel reptile, pronounced list-row-sore-uss) was a genus of Early Triassic Period therapsids, which lived approximately 250 million years ago in what is now Antarctica, India and South Africa. ... The Induan (also known as the Feixianguanian) is the first stage of the Early Triassic epoch. ... The Triassic is a geologic period that extends from about 251 to 200 Ma (million years ago). ... Kannemeyeridae: A family of large, stocky, beaked and sometimes tusked dicynodonts, they were the dominant large terrestrial herbivores through most of the Triassic period. ... The Olenekian (also known as the Yongningzhenian) is a stage of the Early Triassic epoch. ... The Ladinian (also known as the Falangian) is a stage of the Middle Triassic epoch. ... The Carnian is a stage on the geologic time scale occuring from 228 +/- 2 to 216. ... Genera Traversodon Boreogomphodon Luangwa Massetognathus Dadadon Gomphodontosuchus Scalenodontoides Exaeretodon Traversodontidae is an advanced, large, plant-eating group of cynodonts that is part of the lineage Cynognathia, a line that includes the famous, fierce predator Cynognathus. ... Genera Mesosuchus Howesia Stenaulorhynchys Rhynchosaurus Otischalia Isalorhynchus Hyperodepedon Rhynchosaurs were a group of unusual Triassic diapsid reptiles related to the archosaurs. ... The Norian Stage was a portion of the Triassic geological period. ... Groups Saturnalia Prosauropoda Sauropoda The Sauropodomorpha were a group of long-necked, herbivorous dinosaurs that eventually dropped down on all fours and became the largest animals that ever the walked the earth. ... Orders Saurischia    Sauropodomorpha    Theropoda Ornithischia Dinosaurs are giant reptiles that dominated the terrestrial ecosystem for most of their 165-million year existence. ...

With the decline and extinction of the Kannemeyerids, there were to be no more dominant large synapsid herbivores until the middle Paleocene epoch. Orders & Suborders Order Pelycosauria * Suborder Caseasauria Suborder Eupelycosauria * Order Therapsida * Suborder Biarmosuchia Suborder Dinocephalia Suborder Anomodontia Suborder Gorgonopsia Suborder Therocephalia Suborder Cynodontia * For complete phylogeny, see text. ... The Paleocene, early dawn of the recent, is a geologic epoch that lasted from 65. ...

It used to be thought that Dicynodonts died out completely before the end of the Triassic. Recently however, evidence has come to light showing the dicynodonts survived into the Cretaceous in southern Gondwana (now Queensland) (Thulborn and Turnmer, 2003). If authentic, this is an astonishing example of a Lazarus taxon. The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... Gondwanaland redirects here. ... Capital Brisbane Government Constitutional monarchy Governor Quentin Bryce Premier Peter Beattie (ALP) Federal representation  - House seats 28  - Senate seats 12 Gross State Product (2004-05)  - Product ($m)  $158,506 (3rd)  - Product per capita  $40,170/person (6th) Population (End of September 2006)  - Population  4,070,400 (3rd)  - Density  2. ... The takahe is an example of a Lazarus taxon. ...

Taxonomy and Phylogeny

• Suborder Anomodontia
• Infraorder Dicynodontia
  • Superfamily Eodicynodontoidea
    • Family Eodicynodontidae
      • Eodicynodon
  • Diictodontia
    • Robertoidea
      • Family Robertiidae
        • Robertia
      • Family Diictodontidae
        • Anomodon
        • Diictodon
      • Superfamily Emydopoidea
        • Family Emydopidae
          • Emydops
          • Myosauroides
          • Palemydops
        • Family Cistecephalidae
          • Cistecephaloides
          • Cistecephalus
          • Kawingasaurus
  • Superfamily Kingorioidea
    • Family Kingoriidae
      • Kingoria
      • Kombusia
  • Colobodectes
  • Pristerodontia
    • Family Pristerodontidae
    • Family Oudenodontidae
    • Family Aulacocephalodontidae
    • Family Lystrosauridae
    • Family Dicynodontidae
    • Superfamily Kannemeyeriiformes
      • Family Shanisiodontidae
      • Family Stahleckeriidae
      • Family Kannemeyeriidae

Groups Anomocephalus Patranomodon Venyukoviidae Dromasauria Dicynodontia The Anomodontia are one of the three major groups of therapsids. ... Binomial name Robertia broomiana Robertia broomiana was a small, primitive dicynodont; among the earlier members of the group. ... Diictodon was an extermely common theraspid, roughly 18 inches long. ... There are very few or no other articles that link to this one. ... Cistecephalus was a small, specialised, burrowing dicynodont, a kind of reptilian mole. ... Kannemeyeriidae: A family of large, stocky, beaked and sometimes tusked dicynodonts, they were the dominant large terrestrial herbivores through most of the Triassic period. ...

See also

• Dicynodon

Species D. trautscholdi Dicynodon (Two Dog-teeth) is a type of herbivorous mammal-like reptile that flourished during the Permian Period. ...

References

• Carroll, R. L. (1988), Vertebrate Paleontology and Evolution, WH Freeman & Co.
• Colbert, E. H., (1969), Evolution of the Vertebrates, John Wiley & Sons Inc (2nd ed.)
• Cox, B., Savage, R.J.G., Gardiner, B., Harrison, C. and Palmer, D. (1988) The Marshall illustrated encyclopedia of dinosaurs & prehistoric animals, 2nd Edition, Marshall Publishing
• Crompton, A. W, and Hotton, N. 1967. Functional morphology of the masticatory apparatus of two dicynodonts (Reptilia, Therapsida). Postilla, 109:1–51.
• King, Gillian M., "Anomodontia" Part 17 C, Encyclopedia of Paleoherpetology, Gutsav Fischer Verlag, Stuttgart and New York, 1988
• -- -- , 1990, the Dicynodonts: A Study in Palaeobiology, Chapman and Hall, London and New York
• Thulborn, Tony and Turner, Susan, 2003, "The last dicynodont: an Australian Cretaceous relict" Proceedings: Biological Sciences Vol 270, No 1518 / May 07, 2003; pp 985 - 993

Robert L. Carroll (b. ... Edwin H. Colbert (1905 – 2001) was a distinguished vertebrate paleontologist and prolific researcher and author. ... Gillian King has worked in teaching and research in paleontology, as Assistant Curator at the Zoological Collections at Oxford University Museum, and a Fellow and Tutor as St Hildas College, Oxford. ...

External link

• Therapsida : Neotherapsida : Dicynodontia - Palaeos