Carnivora

Carnivora Temporal range: Paleocene to Recent
Gray Wolf
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora Bowdich, 1821
Families
17, See classification

The diverse order Carnivora (IPA: [kɑː(ɹ)ˈnɪvɔːˌɹə] or IPA: [kɑː(ɹ)ˈnɪvəɹə]; from Latin carō (stem carn-) 'flesh', + vorāre 'to devour') includes over 260 placental mammals. While the Giant Panda is almost exclusively an herbivore (it occasionally eats fish, eggs and insects), nearly all others eat meat as their primary diet item: some (like the cat family) almost exclusively, others (like the bears and foxes) are more omnivorous. Members of Carnivora have a characteristic skull shape, and their dentition includes prominent canines and carnassials.

Phylogeny

Older classification schemes divided the order into two suborders, Fissipedia (which included the families of primarily land Carnivora) and Pinnipedia (which included the true seals, eared seals, and walrus). However, even at the time, it was recognized that the Fissipedia was a paraphyletic group: the pinnipeds were not the sister group to the fissipeds but rather had arisen from among them.

Newer classification schemes have been able to integrate the findings from molecular techniques for discovering genetic relationships. They generally divide the Carnivora into the suborders Feliformia (cat-like) and Caniformia (dog-like), the latter of which includes the pinnipeds. The pinnipeds are part of a clade, known as the Arctoidea, which also includes the bears and the superfamily Musteloidea. The Musteloidea in turn consists of the mustelids, procyonids, skunks and Ailurus. The dogs are the sister group to the entire arctoid assemblage; they were the first of the extant caniforms to split from the others.

The same studies finally resolve the exact position of Ailurus: the Red Panda is neither a procyonid nor an ursid, but forms a monotypic family with the other musteloids as its closest living relatives. The same study also shows that the mustelids are not a primitive family, as was once thought. Their small body size is a secondary trait — the primitive body form of the arctoids was large, not small.

Recent molecular studies suggest that the endemic Carnivora of Madagascar, including three genera usually classed with the civets and four genera of mongooses classed with the Herpestidae, are all descended from a single ancestor. They form a single sister taxon to the Herpestidae. The hyenas are also closely related to this clade.

The exact position of the cats in relation to the other families is somewhat disputed. Nandinia, the African Palm Civet, seems to be the most primitive of all the feliforms and the very first to split from the others. The Asiatic linsangs of the genus Prionodon (traditionally placed in the Viverridae) might form a family of their own as well, as some recent studies indicate that Prionodon is actually the closest living relative to the cats.

The position of extinct Carnivora families is not clear. Recent studies suggest that the ancient families Miacidae and Viverravidae are not basal members of the Caniformia and Feliformia, so they are not the direct ancestors of any living Carnivora family. The Miacidae is not even monophyletic, rather it appears to represent a paraphyletic array of stem taxa. Traditionally, the Miacidae and the Viverravidae have been classified in a third, extinct paraphyletic superfamily, the Miacoidea, from which the direct ancestors of the other two superfamilies arose.

The Nimravidae are sometimes seen as the most basal of all feliforms, and the first to split from the others. Other studies indicate that Barbourofelids forms a seperate family, which is closely related to the true felids instead of being related to the Nimravids. The position of many extinct felids is not clear — they may or may not be true cats after all. The amphicyonids are the first of the caniforms to split off — they are not the sister group to the ursids (as most scientists once thought) but are rather an outgroup to all other caniforms.

The results of the same study further suggest a much younger minimum age for the crown-clade Carnivora (the divergence age of the subclades Caniformia and Feliformia) than had been inferred in many previous studies: middle-Eocene (ca. 43 million years ago), rather than early Paleocene (60 Ma). It remains unknown if the Creodonta are the closest relatives of the Carnivora, but it seems they are. They are united with the Pholidota and some extinct orders in the clade Ferae.

Classification

• ORDER CARNIVORA
  • Suborder Feliformia ("cat-like")
    • Family †Nimravidae: false sabre-tooths
    • Family Nandiniidae: African Palm Civet; 1 species in 1 genus
    • Superfamily Feloidea
      • Family Prinonodontidae: Asiatic linsangs; 2 species in 1 genus
      • Family †Barbourofelidae: false sabre-tooths
      • Family Felidae: cats; 40 species in 14 genera
    • Superfamily/Clade Viverroidea?
      • Family Viverridae: civets and allies; 35 species in 15 genera
      • Superfamily Herpestoidea?
        • Family Hyaenidae: hyenas and aardwolf; 4 species in 3 genera
        • Family Eupleridae : Malagasy carnivores; 8 species in 7 genera
        • Family Herpestidae: mongooses and allies; 33 species in 14 genera
  • Suborder Caniformia ("dog-like")
    • Family †Miacidae (34-64 Ma)
    • Family †Amphicyonidae: Bear-dogs (9-37 Ma)
    • Family Canidae: dogs and allies; 37 species in 10 genera
    • Superfamily/Clade Arctoidea
      • Family Ursidae: bears; 8 species in 4 genera
      • Superfamily Musteloidea
        • Family Ailuridae: Red Panda; 1 species in 1 genus.
        • Family Mephitidae: skunks and stink badgers; 10 species in 3 genera
        • Family Mustelidae: weasels, martens, badgers, and otters; 55 species in 24 genera
        • Family Procyonidae: raccoons and allies; 19 species in 6 genera
      • Superfamily Pinnipedia:
        • Family Odobenidae: Walrus; 1 species in 1 genus
        • Family Otariidae: sea lions, eared seals, fur seals; 14 species in 7 genera
        • Family Phocidae: true seals; 19 species in 9 genera

Cladogram

Carnivora 
  ├─ Caniformia'
  │ ├─ ?Miacidae †
  │ ├─ Amphicyonidae †
  │ ├─ Canidae    
  │ └─ Arctoidea
  │    ├─ Ursidae 
  │    └─ +
  │       ├─ Pinnipedia 
  │       │  ├─ Phocidae        
  │       │  └─ +
  │       │     ├─ Otariidae          
  │       │     └─ Odobenidae 
  │       │ 
  │       └─ Musteloidea
  │            ├─ Ailuridae       
  │            └─ +
  │               ├─ Mephitidae         
  │               └─ +
  │                  ├─ Procyonidae         
  │                  └─ Mustelidae 
  │
  └─ Feliformia
       ├─ ?Viverravidae †
       ├─ ?Nimravidae †
       ├─ Nandiniidae 
       └─ +
          ├─ +
          │  ├─ Prionodontidae
          │  └─ Felidae
          │  
          └─ +
             ├─ Viverridae
             └─ +
                ├─ Hyaenidae 
                └─ +
                   ├─ Herpestidae 
                   └─ Eupleridae

See also

• Detailed list of the families and genera of the order Carnivora
• Cat-fox, a new carnivore discovered on Borneo

References

• Flynn et al: Molecular Phylogeny of Carnivora
• Wesley-Hunt: Phylogeny of the Carnivores
• High-Resolution Images of Carnivore Brains