The Probainognathians are one of the two major clades of the infraorder Eucynodontia

Eucynodontia

Eucynodontia is a grouping of animals that includes both mammals, such as dogs, and mammal-like non-mammalian therapsids such as cynodonts . Its membership was and is made up of both carnivores and herbivores. The chronological range extends from at least the Lower Triassic, possibly the Upper...

, the other being Cynognathia

Cynognathia

The Cynognathians are one of the two major clades of the infraorder Eucynodontia, the other being the Probainognathians. Cynognathus, the most basal representative of the clade was a carnivore, unlike most cynognathians. The cynognathians were mostly mammal-like, but the subgroup Tritylodontids...

ns. They were mostly carnivorous

Carnivore

A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...

, though some species may have evolved omnivorous

Omnivore

Omnivores are species that eat both plants and animals as their primary food source...

 traits. The Probainognathia form into four groups: Probainognathidae

Probainognathidae

Probainognathidae is an extinct family of meat-eating mammal-like reptiles which lived during the Upper Triassic. According to some authors, it has perhaps two known members: Probainognathus from South America, and the somewhat later Lepagia from Europe. The family was established by Romer in 1973...

, Chiniquodontidae

Chiniquodontidae

Chiniquodontidae is a family of meat-eating advanced mammal-like reptiles that lived during the Upper Triassic of South America and perhaps Europe. A further possible representative, Aleodon, has been identified from the Middle Triassic of Africa...

, Tritheledontidae, and Mammaliaformes

Mammaliaformes

Mammaliaformes is a clade that contains the mammals and their closest extinct relatives. Phylogenetically, it is defined as a clade including the most recent common ancestor of Sinoconodon, morganuconodonts, docodonts, Monotremata, Marsupialia, Placentalia, extinct members of this clade, and all...

. The earliest and most basal Probainognathian is Lumkuia

Lumkuia

Lumkuia is an extinct genus of probainognathian cynodont. It is the earliest and most basal known member of Probainognathia, with fossils being found from the Lystrosaurus Assemblage Zone of the Beaufort Group in the South African Karoo Basin that date back to the early Middle Triassic...

, from South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

. Non-mammalian probainognathians lived from Triassic

Triassic

The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...

 to Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

, making this clade one of the longest lived therapsid family.

Taxonomy

• Suborder Cynodontia
  • Infraorder Eucynodontia
    Eucynodontia
    Eucynodontia is a grouping of animals that includes both mammals, such as dogs, and mammal-like non-mammalian therapsids such as cynodonts . Its membership was and is made up of both carnivores and herbivores. The chronological range extends from at least the Lower Triassic, possibly the Upper...
    
    
    • (unranked) Probainognathia
      • Family Probainognathidae
        Probainognathidae
        Probainognathidae is an extinct family of meat-eating mammal-like reptiles which lived during the Upper Triassic. According to some authors, it has perhaps two known members: Probainognathus from South America, and the somewhat later Lepagia from Europe. The family was established by Romer in 1973...
        
        
        • Probainognathus
          Probainognathus
          Probainognathus is a genus of meat-eating mammal-like reptile that lived during the lower Upper Triassic of South America. This creature had an incipient squamosal-dentary jaw-cranium joint, which is a clearly mammalian anatomical feature. It was at the very least closely related to the family of...
          
          
      • Superfamily Chiniquodontoidea
        Chiniquodontoidea
        Chiniquodontoidea is a clade of cynodonts that is defined as including all probainognathians closer to mammals than to Probainognathus which is the more primitive form in Probainognathia....
        
        
        • Family Chiniquodontidae
          Chiniquodontidae
          Chiniquodontidae is a family of meat-eating advanced mammal-like reptiles that lived during the Upper Triassic of South America and perhaps Europe. A further possible representative, Aleodon, has been identified from the Middle Triassic of Africa...
          
          
        • (unranked) Ictidosauria
          • Riograndia
            Riograndia
            Riograndia is a genus of tritheledontid cynodont from the Late Triassic of South America. The type species is R. guaibensis. Riograndia guaibensis was estimated to have been about 15 cm long and 30 g in weight. Remains have been found in the Caturrita Formation of the geopark of Paleorrota...
            
            
          • Family Tritheledontidae
            • Trithelodon
              Trithelodon
              Trithelodon was an extinct genus of a group of mammal-like reptiles called cynodonts. Like cynodonts, Trithelodon had many traits shared by mammals. Trithelodon was probably an insectivore, and nocturnal....
              
              
        • Mammaliamorpha
          • Prozostrodon
            Prozostrodon
            Prozostrodon was an advanced cynodont that was closely related to the ancestors of mammals. Its relatives gave rise to the first mammaliformes. Prozostrodon were found in the Geopark of Paleorrota, Santa Maria Formation, Brazil. This deposited in Geosciences of UFRGS....
            
            
          • Mammaliaformes
            Mammaliaformes
            Mammaliaformes is a clade that contains the mammals and their closest extinct relatives. Phylogenetically, it is defined as a clade including the most recent common ancestor of Sinoconodon, morganuconodonts, docodonts, Monotremata, Marsupialia, Placentalia, extinct members of this clade, and all...
            
            *
            • Class Mammalia

Phylogeny

Probainognathia
|-Probainognathidae

Probainognathidae

Probainognathidae is an extinct family of meat-eating mammal-like reptiles which lived during the Upper Triassic. According to some authors, it has perhaps two known members: Probainognathus from South America, and the somewhat later Lepagia from Europe. The family was established by Romer in 1973...

`-Chiniquodontoidea

Chiniquodontoidea

Chiniquodontoidea is a clade of cynodonts that is defined as including all probainognathians closer to mammals than to Probainognathus which is the more primitive form in Probainognathia....

|-Chiniquodontidae

Chiniquodontidae

Chiniquodontidae is a family of meat-eating advanced mammal-like reptiles that lived during the Upper Triassic of South America and perhaps Europe. A further possible representative, Aleodon, has been identified from the Middle Triassic of Africa...

`-Ictidosauria
|-Tritheledontidae
`-+-Prozostrodon

Prozostrodon

Prozostrodon was an advanced cynodont that was closely related to the ancestors of mammals. Its relatives gave rise to the first mammaliformes. Prozostrodon were found in the Geopark of Paleorrota, Santa Maria Formation, Brazil. This deposited in Geosciences of UFRGS....

`-Mammaliaformes

Mammaliaformes

Mammaliaformes is a clade that contains the mammals and their closest extinct relatives. Phylogenetically, it is defined as a clade including the most recent common ancestor of Sinoconodon, morganuconodonts, docodonts, Monotremata, Marsupialia, Placentalia, extinct members of this clade, and all...

`-Mammalia

See also

• Evolution of mammals
  Evolution of mammals
  __FORCETOC__The evolution of mammals within the synapsid lineage was a gradual process that took approximately 70 million years, beginning in the mid-Permian. By the mid-Triassic, there were many species that looked like mammals, and the first true mammals appeared in the early Jurassic...
  
  
• Prehistoric mammal
  Prehistoric mammal
  Prehistoric mammals are groups of mammals that lived before humans developed writing. 164 million years ago, in the Jurassic period, Castorocauda lutrasimilis, a mammal-like animal weighing about 500 grams , had a full mammalian pelt, with guard hairs and under fur, webbed feet, and scales on the...
  
  s
• List of prehistoric mammals