Difference between revisions of "Ungulate" - New World Encyclopedia

From New World Encyclopedia
Line 1: Line 1:
−
'''Ungulates''', or hoofed [[mammal]]s, are members of the orders Perissodactyla and Artiodactyla.  Ungulates include most of the large land mammals on earth and all of the large domestic animals kept by humans. They are found naturally on all continents except Antartica and Australia (where they were introduced by humans) and in almost all environments from forests to grasslands to deserts to high mountains to the tundra.  They range in size from the Lesser Malay mouse deer, ''Tragulus javanicus'', which weighs 1.5 to 2.5 kg (3.3 to 5.5 lbs) fully grown to the White rhinoceros, ''Ceratotherium simum'', and the Hippotomus, ''Hippopotamus amphibius'', which can weigh over 3,200 kg (7,000 lbs) (Huffman 2006).  
+
'''Ungulates''', or hoofed [[mammal]]s, are members of the orders Perissodactyla and Artiodactyla.  Ungulates include most of the large land mammals on earth and all of the large domestic animals kept by humans. They are found naturally on all continents except Antarctica and Australia (where they were introduced by humans) and in almost all environments from forests to grasslands to deserts to high mountains to the tundra.  They range in size from the Lesser Malay mouse deer, ''Tragulus javanicus'', which weighs 1.5 to 2.5 kg (3.3 to 5.5 lbs) to the White rhinoceros, ''Ceratotherium simum'', and the Hippopotamus, ''Hippopotamus amphibius'', which can weigh over 3,200 kg (7,000 lbs) (Huffman 2006).  
  
 
Closely related to ungulates are the orders:
 
Closely related to ungulates are the orders:
Line 24: Line 24:
 
{{Taxobox_ordo_entry | taxon = '''Perissodactyla'''}}<br/>{{Taxobox authority | author = [[Richard Owen|Owen]] | date = 1848}}
 
{{Taxobox_ordo_entry | taxon = '''Perissodactyla'''}}<br/>{{Taxobox authority | author = [[Richard Owen|Owen]] | date = 1848}}
 
{{Taxobox_end_placement}}
 
{{Taxobox_end_placement}}
−
{{Taxobox_section_subdivision | color = pink | plural_taxon = Families}}
 
−
[[Equidae]]<br />
 
−
[[Tapiridae]]<br />
 
−
[[Rhinocerotidae]]<br />
 
−
[[Brontotheriidae]] [[extinction|† (extinct)]]<br />
 
−
[[Chalicotheriidae]] †<br />
 
−
[[Hyracodontidae]] †<br />
 
−
 
 
{{Taxobox_end}}
 
{{Taxobox_end}}
  
 
In the Perissodactyla, the odd-toed ungulates, the central axis of the foot passes through the third toe.   
 
In the Perissodactyla, the odd-toed ungulates, the central axis of the foot passes through the third toe.   
  
−
==Evolution==
+
===Evolution===
 
The odd-toed ungulates arose in what is now [[North America]] in the late [[Paleocene]], less than 10 million years after the [[dinosaur]]s died out. By the start of the [[Eocene]] (55 million years ago) they had diversified and spread out to occupy several continents. The horses and tapirs both evolved in North America; the rhinoceroses appear to have developed in [[Asia]] from tapir-like animals and then spread to the Americas during the middle Eocene (about 45 million years ago). There were 12 families, of which only three survive. These families were very diverse in form and size; they included the enormous Brontotheres and the bizarre Chalicotheres. The largest perissodactyl, an Asian rhinoceros called Paraceratherium, reached 11,000 kg (12 tons), more than twice the weight of an elephant.
 
The odd-toed ungulates arose in what is now [[North America]] in the late [[Paleocene]], less than 10 million years after the [[dinosaur]]s died out. By the start of the [[Eocene]] (55 million years ago) they had diversified and spread out to occupy several continents. The horses and tapirs both evolved in North America; the rhinoceroses appear to have developed in [[Asia]] from tapir-like animals and then spread to the Americas during the middle Eocene (about 45 million years ago). There were 12 families, of which only three survive. These families were very diverse in form and size; they included the enormous Brontotheres and the bizarre Chalicotheres. The largest perissodactyl, an Asian rhinoceros called Paraceratherium, reached 11,000 kg (12 tons), more than twice the weight of an elephant.
  
Line 44: Line 36:
  
  
−
==Taxonomy==
+
===Perissodactyla families===
−
The members of the order fall into two suborders:
+
 
−
*'''''Hippomorpha''''' are odd-toed ungulates that are fast runners with long legs and have only one toe; this suborder has the sole family ''Equidae'' (coextensive with the genus ''Equus''), comprising the horse, zebra, donkey, onager, and allied species.
+
*Tapiridae - Tapirs
−
*'''''Ceratomorpha''''' are odd-toed ungulates that have several functional toes and are heavier than and move slower than the ''Hippomorpha'' species. This suborder has two families: Tapiridae (tapirs) and Rhinocerotidae (rhinoceroses)
+
*Rhinocerotidae - Rhinoceroses
 +
*Equidae - Horses
  
 
==Even-toed ungulates==
 
==Even-toed ungulates==
Line 59: Line 52:
 
{{Taxobox_ordo_entry | taxon = '''Artiodactyla'''}}<br/>{{Taxobox authority | author = [[Richard Owen|Owen]] | date = 1848}}
 
{{Taxobox_ordo_entry | taxon = '''Artiodactyla'''}}<br/>{{Taxobox authority | author = [[Richard Owen|Owen]] | date = 1848}}
 
{{Taxobox_end_placement}}
 
{{Taxobox_end_placement}}
−
{{Taxobox_section_subdivision | color = pink | plural_taxon = Families}}
 
−
[[Antilocapridae]]<br>
 
−
[[Bovidae]]<br>
 
−
[[Camelidae]]<br>
 
−
[[Cervidae]]<br>
 
−
[[Giraffidae]]<br>
 
−
[[Hippopotamidae]]<br>
 
−
[[Moschidae]]<br>
 
−
[[Suidae]]<br>
 
−
[[Tayassuidae]]<br>
 
−
[[Tragulidae]]<br>
 
−
[[Leptochoeridae]] [[extinction|† (extinct)]]<br>
 
−
[[Chaeropotamidae]] †<br>
 
−
[[Dichobunidae]] †<br>
 
−
[[Cebochoeridae]] †<br>
 
−
[[Entelodontidae]] †<br>
 
−
[[Anoplotheriidae]] †<br>
 
−
[[Anthracotheriidae]] †<br>
 
−
[[Cainotheriidae]] †<br>
 
−
[[Agriochoeridae]] †<br>
 
−
[[Merycoidodontidae]] †<br>
 
−
[[Leptomerycidae]] †<br>
 
−
[[Protoceratidae]] †<br>
 
−
[[Xiphodontidae]] †<br>
 
−
[[Amphimerycidae]] †<br>
 
−
[[Gelocidae]] †<br>
 
−
[[Merycodontidae]] †<br>
 
−
[[Dromomerycidae]] †<br>
 
 
{{Taxobox_end}}
 
{{Taxobox_end}}
  
  
−
The '''even-toed ungulates''' form the [[mammal]] [[order (biology)|order]] '''Artiodactyla'''. They are [[ungulate]]s whose weight is borne about equally by the third and fourth toes, rather than mostly or entirely by the third as in [[perissodactyls]]. There are about 220 artiodactyl [[species]], including many that are of great [[economic]] importance to [[human]]s.
+
In Artiodactyla, even-toed ungulates, the axis of the leg passes between the third and forth toes.
−
 
 
−
As with many mammal groups, even-toed ungulates first appeared during the Early [[Eocene]] (about 54 million years ago). In form they were rather like today's [[chevrotain]]s: small, short-legged creatures that ate [[leaves]] and the soft parts of [[plants]]. By the Late Eocene (46 million years ago), the three modern suborders had already developed: [[Suina]] (the [[pig]] group); [[Tylopoda]] (the [[camel]] group); and [[Ruminantia]] (the [[goat]] and [[cattle]] group). Nevertheless, artiodactyls were far from dominant at that time: the [[odd-toed ungulate]]s (ancestors of today's [[horse]]s and [[Rhinoceros|rhino]]s) were much more successful and far more numerous. Even-toed ungulates survived in niche roles, usually occupying marginal [[habitat (ecology)|habitats]], and it is presumably at that time that they developed their complex [[digestive system]]s, which allowed them to survive on lower-grade feed.
 
−
 
 
−
The appearance of [[Poaceae|grasses]] during the [[Eocene]] and their subsequent spread during the [[Miocene]] (about 20 million years ago) saw a major change: grasses are very difficult to digest and the even-toed ungulates with their highly-developed [[stomach]]s were better able to adapt to this coarse, low-[[nutrition]] diet, and soon replaced the odd-toed ungulates as the dominant [[Landform|terrestrial]] [[herbivore]]s.
 
−
 
 
−
The artiodactyls fall into two groups which, despite underlying similarities, are rather different. The Suina (pigs, [[hippopotamus|hippos]], and [[peccary|peccaries]]) retain four toes, have simpler [[molar (tooth)|molars]], short legs, and their [[canine teeth]] are often enlarged to form [[tusk]]s. In general, they are [[omnivore]]s and have a simple stomach (the two hippopotamus species and the [[babirusa]] are exceptions). It is possible that Suina is not a natural group. In particular, recent research suggests that the Hippopotamidae (which are likely derived from among the extinct group known as [[Anthracotherium|anthracotheres]]) may be more closely related to the ruminants than to the pigs.
 
−
 
 
−
The camelids and the Ruminantia, on the other hand, tend to be longer-legged, to have only two toes, to have more complex cheek teeth well-suited to grinding up tough grasses, and multi-chambered stomachs. Not only are their digestive systems highly developed, they have also evolved the habit of chewing [[cud]]: regurgitating partly-digested food to chew it again and extract the maximum possible benefit from it.
 
−
 
 
−
Lastly a group of artiodactyls, which [[molecular biology]] suggests were most closely related to Hippopotamidae, returned to the sea [[Evolution of cetaceans|to become whales]]. The conclusion is that Artiodactyla, if it excludes [[Cetacea]], is a [[Paraphyly|paraphyletic group]]. For this reason, the term '''[[Cetartiodactyla]]''' was coined to refer to the group containing both artiodactyls and whales (though the problem could just as easily be resolved by recognizing Cetacea as a subgroup of Artiodactyla).
 
  
 +
===Evolution===
 +
As with many mammal groups, even-toed ungulates first appeared during the Early [[Eocene]] (about 54 million years ago). In form they were rather like today's chevrotains: small, short-legged creatures that ate leaves and the soft parts of plants. By the Late Eocene (46 million years ago), the three modern suborders had already developed: Suina (the [[pig]] group); Tylopoda (the [[camel]] group); and Ruminantia (the [[antelope]] group). Nevertheless, artiodactyls were far from dominant at that time: the odd-toed ungulates were much more successful and far more numerous. Even-toed ungulates survived in niche roles, usually occupying marginal habitats, and it is presumably at that time that they developed their complex digestive systems, which allowed them to survive on lower-grade feed.
  
−
* '''ORDER ARTIODACTYLA'''
+
The appearance of [[grass]]es during the Eocene and their subsequent spread during the [[Miocene]] (about 20 million years ago) saw a major change: grasses are very difficult to digest and the even-toed ungulates with their highly-developed [[stomach]]s were better able to adapt to this coarse, low-nutrition diet, and soon replaced the odd-toed ungulates as the dominant terrestrial herbivores.
−
** '''Suborder Suina'''
 
−
*** Family [[Suidae]]: pigs
 
−
*** Family [[Hippopotamidae]]: hippos
 
−
*** Family [[Tayassuidae]]: peccaries
 
−
** '''Suborder Tylopoda'''
 
−
*** Family [[Camelidae]]: camels and [[llama]]s
 
−
** '''Suborder [[Ruminantia]]'''
 
−
*** Family [[Tragulidae]]: chevrotains
 
−
*** Family [[Moschidae]]: musk deer
 
−
*** Family [[Cervidae]]: [[deer]]
 
−
*** Family [[Giraffidae]]: [[Giraffe]] and [[Okapi]]
 
−
*** Family [[Antilocapridae]]: pronghorn
 
−
*** Family [[Bovidae]]: cattle, goats, [[sheep]], and [[antelope]]
 
  
 +
===Artiodactyla families===
  
 +
*Suina - Pigs
 +
*Tayassuidae - Peccaries
 +
*Hippopotamidae - Hippopotamuses
 +
*Camelidae - Camels, llamas
 +
*Tragulidae - Mouse deer
 +
*Cervidae - Deer, elk, moose
 +
*Giraffidae - Giraffes
 +
*Antilocapridae - Pronghorn
 +
*Bovidae - Antelopes, cattle, goats, sheep
  
 
==References==
 
==References==

Revision as of 20:34, 31 October 2006

Ungulates, or hoofed mammals, are members of the orders Perissodactyla and Artiodactyla. Ungulates include most of the large land mammals on earth and all of the large domestic animals kept by humans. They are found naturally on all continents except Antarctica and Australia (where they were introduced by humans) and in almost all environments from forests to grasslands to deserts to high mountains to the tundra. They range in size from the Lesser Malay mouse deer, Tragulus javanicus, which weighs 1.5 to 2.5 kg (3.3 to 5.5 lbs) to the White rhinoceros, Ceratotherium simum, and the Hippopotamus, Hippopotamus amphibius, which can weigh over 3,200 kg (7,000 lbs) (Huffman 2006).

Closely related to ungulates are the orders:

  • Tubulidentata - Aardvark
  • Hyracoidea - Hyraxes
  • Proboscidea - Elephants
  • Sirenia - Sea cows
  • Cetacea - Whales and Dolphins

Ungulate features

The word "ungulate" comes from the Latin word ungula meaning "hoof". A hoof is a claw or nail which protects the toe and enables it to support the weight of the animal. Ungulates stand and run on the tips of their toes. This gives them longer legs which helps them to run faster.

Ungulates are typically herbivores, eating plants; some, such as the pigs, are omnivores, eating a variety of foods including meat.

Perissodactyla: odd-toed ungulates

Odd-toed ungulates
00296 zebra.jpg
Plains Zebras
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Perissodactyla
Owen, 1848

In the Perissodactyla, the odd-toed ungulates, the central axis of the foot passes through the third toe.

Evolution

The odd-toed ungulates arose in what is now North America in the late Paleocene, less than 10 million years after the dinosaurs died out. By the start of the Eocene (55 million years ago) they had diversified and spread out to occupy several continents. The horses and tapirs both evolved in North America; the rhinoceroses appear to have developed in Asia from tapir-like animals and then spread to the Americas during the middle Eocene (about 45 million years ago). There were 12 families, of which only three survive. These families were very diverse in form and size; they included the enormous Brontotheres and the bizarre Chalicotheres. The largest perissodactyl, an Asian rhinoceros called Paraceratherium, reached 11,000 kg (12 tons), more than twice the weight of an elephant.

Perissodactyls were the dominant group of large terrestrial browsers right through the Oligocene. However, the rise of grasses in the Miocene (about 20 million years ago) saw a major change: the even-toed ungulates with their more complex stomachs were better able to adapt to a coarse, low-nutrition diet, and soon rose to prominence. Nevertheless, many odd-toed species survived and prospered until the late Pleistocene (about 10,000 years ago) when they faced the pressure of human hunting and habitat change.

Today there are only 17 species of odd-toes ungulates still living and all of them are in danger of extinction except for the horse and the donkey (UCMP 2006).


Perissodactyla families

  • Tapiridae - Tapirs
  • Rhinocerotidae - Rhinoceroses
  • Equidae - Horses

Even-toed ungulates

Even-toed ungulates
240px
Rocky Mountain Goat, Oreamnos americanus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Owen, 1848


In Artiodactyla, even-toed ungulates, the axis of the leg passes between the third and forth toes.

Evolution

As with many mammal groups, even-toed ungulates first appeared during the Early Eocene (about 54 million years ago). In form they were rather like today's chevrotains: small, short-legged creatures that ate leaves and the soft parts of plants. By the Late Eocene (46 million years ago), the three modern suborders had already developed: Suina (the pig group); Tylopoda (the camel group); and Ruminantia (the antelope group). Nevertheless, artiodactyls were far from dominant at that time: the odd-toed ungulates were much more successful and far more numerous. Even-toed ungulates survived in niche roles, usually occupying marginal habitats, and it is presumably at that time that they developed their complex digestive systems, which allowed them to survive on lower-grade feed.

The appearance of grasses during the Eocene and their subsequent spread during the Miocene (about 20 million years ago) saw a major change: grasses are very difficult to digest and the even-toed ungulates with their highly-developed stomachs were better able to adapt to this coarse, low-nutrition diet, and soon replaced the odd-toed ungulates as the dominant terrestrial herbivores.

Artiodactyla families

  • Suina - Pigs
  • Tayassuidae - Peccaries
  • Hippopotamidae - Hippopotamuses
  • Camelidae - Camels, llamas
  • Tragulidae - Mouse deer
  • Cervidae - Deer, elk, moose
  • Giraffidae - Giraffes
  • Antilocapridae - Pronghorn
  • Bovidae - Antelopes, cattle, goats, sheep

References
ISBN links support NWE through referral fees

  • Huffman, B. 2006 The Ultimate Ungulate Page Website [1]
  • Nowak, R.M. and Paradiso, J.L. 1983. Walker's Mammals of the World. Baltimore, Maryland, USA : The Johns Hopkins University Press
  • University of California Museum of Paleontology (UCMP) 2006. "Ungulates: Hoofed Mammals"[2]
  • Voelker, W. 1986. The Natural History of Living Mammals. Medford, New Jersey, USA : Plexus Publishing, Inc.

Credits

New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here:

The history of this article since it was imported to New World Encyclopedia:

Note: Some restrictions may apply to use of individual images which are separately licensed.

Retrieved from https://www.newworldencyclopedia.org/p/index.php?title=Ungulate&oldid=131312

Content is available under Creative Commons Attribution/Share-Alike License; additional terms may apply. See Terms of Use for details.
Copyright Logo
Powered by MediaWiki