Cervidae introduction

Family Cervidae

Cervidae (4 suborders; 16 generals; 54 species) are found in a wide variety of habitats, and the majority of them inhabit temperate mixed deciduous forest, mountain mixed coniferous forest, tropical seasonal/dry forest, and savanna habitats around the world. They are widely distributed in all continents except Antarctica and Australia, though Africa has only one native deer, the Barbary stag, a subspecies of red deer that is confined to the Atlas Mountains in the northwest of the continent. And fallow deer have been introduced to South Africa.

The Cervidae first appear as fossils in the early Miocene of Asia, where they expanded into a wide variety of niches. During the Miocene, members of this family migrated to North America. After expanding in the Nearctic region, deer crossed to South America during the Pleistocene, when the Panama land bridge formed.

Deer constitute the second most diverse family of Ruminantia after bovids. The Cervidae have species represented in all 3 feeding classes (browsers, grazers, and intermediate feeders). Males of a few species possess enlarged, tusk-like upper canines (Hydropotes, Muntiacus, Elaphodus). In other species the upper canines are either vestigial or absent. They have no gall bladder and usually have two lacrimal canals. The body weight of deer is about 6-550 kg.

Antlers are the defining characteristic of this family: all but one species (Hydropotes inermis) possess these cranial appendages. Antlers are composed entirely of bone and often have elaborate branching patterns. The antlers grow from an extension (the "pedicel") on the skull's frontal bone, joining to the skull in a suture known as a burr. The sutures holding the antlers to the deer's head decalcify on an annual basis (under hormonal control), causing the antlers to fall off (usually in the late fall or early winter in temperate species). After shedding, the antlers soon begin to regrow. During the growth period, the expanding bone is covered with a thin layer of fuzzy skin known as velvet, which helps protect the growing tissue. In the vast majority of species, antlers are borne only by males - only in the reindeer, Rangifer tarandus, do females regularly grow antlers.

Using fossil calibrations, we estimated the emergence of Cervidae at ~20 Mya. Only one deer species, the reindeer has been fully domesticated.

References  

  1. Hackmann T J, Spain J N. Invited review: ruminant ecology and evolution: perspectives useful to ruminant livestock research and production.[J]. Journal of Dairy Science, 2010, 93(4):1320-1334.
  2. Hernández F M, Vrba E S. A complete estimate of the phylogenetic relationships in Ruminantia: a dated species-level supertree of the extant ruminants[M]. 2005.
  3. Hofmann R R. Evolutionary steps of ecophysiological adaptation and diversification of ruminants: a comparative view of their digestive system[J]. Oecologia, 1989, 78(4):443-457.
  4. Davis E B, Brakora K A, Lee A H. Evolution of ruminant headgear: a review[J]. Proceedings Biological Sciences, 2011, 278(1720):2857-2865.
  5. http://www.ultimateungulate.com/ungulates.html
  6. https://en.wikipedia.org/wiki/Deer

The Giraffidae Family Tree