Suina

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Suina
Lightmatter unidentified pig-like animal.jpg
Potamochoerus porcus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Suborder: Suina
Gray, 1868
Families

 Suidae
 Tayassuidae

The suborder Suina (also known as Suiformes) is a lineage of omnivorous non-ruminant artiodactyl mammals that includes the pigs and peccaries of the families Suidae and Tayassuidae and their fossil kin. Hippopotamidae has historically been classified among the Suina for morphological reasons, but is now more often classified as the sister group of the whales, or Cetacea.

Classification[edit]

Cladogram showing the position of Suinamorpha

The suborder Suina includes Suidae (pig family) and Tayassuidae (peccary family).

The Merycoidodonts, or "oreodonts," a branch of the tylopoda, were often considered suines due to the popular, though inaccurate, description of them as "ruminating hogs". Oreodonts were not suines, they were more closely related to camels. Similarly, the entelodonts, had long been classified as members of the Suina. Spaulding et al. have found them to be closer to whales, than to pigs in his Cetacodontamorpha.[1]

Some morphological studies have suggested that the hippopotamus family Hippopotamidae was part of the Suina, but a growing body of morphological and genetic evidence has suggested that they share a common ancestor not with the Suina, but with Cetaceans—the clade that includes whales and dolphins. Whales and artiodactyls form a clade called Cetartiodactyla.[2]


   Cetartiodactyla   

 Tylopoda


   Artiofabula   

 Suina    


   Cetruminantia   

 Ruminantia


   Whippomorpha   

 Hippopotamidae



 Cetacea






The most recent research into the origins of hippopotamidae suggests that hippos and whales shared a common semi-aquatic ancestor that branched off from other Artiodactyls around 60 million years ago.[3] Descendants of this hypothesized ancestor likely split into two branches around 54 million years ago.[4] One branch would evolve into cetaceans, possibly beginning with the proto-whale Pakicetus from 52 million years ago and other early whale ancestors, known as Archaeoceti, which eventually underwent aquatic adaptation into the almost completely aquatic cetaceans.[2]

Anatomy[edit]

The anatomy of the Suina differs from other even-toed ungulates. For example, they have maxillary (upper) teeth in front, which allow for the proper chewing of food. In contrast, other even-toed ungulates, such as goats and deer, have front teeth only on the bottom; this doesn't let them chew very well, thus they swallow and regurgitate their food to allow rumination.

Most even-toed ungulates have a four-chambered stomach. In contrast, the Suina have a simple stomach that allows an omnivorous diet.

Boar skeleton

Most members of Suina have toes rather than hooves. While most artiodactyls have long slender legs, the Suina generally have short, stubby legs.

See also[edit]

References[edit]

External links[edit]