Pecora

Pecora Temporal range: 50–0  Ma PreꞒ Ꞓ O S D C P T J K Pg N Eocene - recent
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Artiodactyla
Suborder:	Ruminantia
Infraorder:	Pecora Flower, 1883[1]
Subgroups
†Dromomerycidae Antilocapridae Bovimorpha Cervoidea Cervidae Bovoidea Bovidae Moschidae Giraffomorpha †Palaeomerycidae Giraffoidea Giraffidae †Climacoceratidae

Pecora is an

It is likely that the antelopes, giraffids, and pronghorns evolved in an open environment while the cervids, including the caribou, evolved in a woodland habitat.[8] The type of gallop in Pecorian species is shown to be closely related to their environment and anatomy, where light Pecorian species use both flexed and extended suspensions in their fast gallops.^[8] The white-tail and mule-deer have been observed to primarily use the extended suspension, since in this phase of their gallop they leap over bushes and logs that are present in their brush environment.^[8] However, heavy Pecorian species do not use extended suspensions as most have backs that slope downward with shorter hind legs.^[8]

Taxonomy and classification

Pecora is an

Current attempts to determine the relationships among pecoran families (as well as all artiodactyls) rely on molecular studies, as little consensus exists in morphological studies.[2] Different families within Pecora are recognized as valid by different groups of scientists.^{[6]and sources therein, pp. 4–5}

Until the beginning of the 21st century it was understood that the family

Ruminantia	Tragulina Tragulidae Pecora Antilocapridae Giraffidae Cervidae Bovidae Moschidae

Infraorder Pecora ("horned ruminants", "higher ruminants")

• Incertae sedis
  • Family †Dromomerycidae
  • Family Antilocapridae (pronghorn)
• Parvorder Bovimorpha
  • Superfamily Cervoidea
    • Family
      Cervidae (deer
      )
  • Superfamily Bovoidea
    • Family Moschidae (musk deer)
    • Family Bovidae (cattle, goats, sheep, and antelopes)
• Parvorder Giraffomorpha
  • Family †Palaeomerycidae
  • Superfamily Giraffoidea
    • Family Giraffidae (giraffes and okapi)
    • Family †Climacoceratidae

Anatomy

Pecorans share characteristics with other artiodactyls, including a four-chambered stomach, and a paraxonic foot, meaning that it supports weight on the third and fourth digits. Several characteristics distinguish Pecora from its sister taxon,

The distinguishing features of most pecoran families are cranial appendages. Most modern pecorans (with the exception of the Moschidae) have one of four types of cranial appendages: horns, antlers, ossicones, or pronghorns.^[6]

• True horns have a bone core that is covered in a permanent sheath of keratin. They are indicative of Bovidae. Horns develop in the periosteum over the frontal bone, and can be curved or straight.^[4] Surface features on the keratin sheath (e.g., ridges or twists) are thought to be caused by differential rates of growth around the bone core.^[4]
• Alces alces
  ).
• Okapia johnstoni
  ).
• Antilocapra americana
  ).