View source for Biology:Digitigrade

{{Short description|Standing or walking on digits/toes; animals which do so}}
In terrestrial [[Biology:Vertebrate|vertebrate]]s, '''digitigrade''' ({{IPAc-en|ˈ|d|ɪ|dʒ|ɪ|t|ɪ|ˌ|g|r|eɪ|d}})<ref>{{Dictionary.com|Digitigrade}}</ref> locomotion is walking or running on the toes (from the Latin ''digitus'', 'finger', and ''gradior'', 'walk'). A digitigrade animal is one that stands or walks with its toes (phalanges) on the ground, and the rest of its foot lifted. Digitigrades include birds (what many see as bird's knees are actually ankles), cats, dogs, and many other [[Biology:Mammal|mammal]]s, but not [[Biology:Plantigrade|plantigrade]]s (such as humans) or [[Biology:Ungulate|unguligrade]]s (such as horses). Digitigrades generally move more quickly than other animals.

[[File:Les différents types de locomotions chez les amniotes.png|thumb|Comparison of lower limb structure. From left to right: plantigrade, digitigrade and unguligrade. In red the basipod, in violet the metapodia, in yellow the phalanges, in brown the keratin nails.]]
There are structural differences between the limb anatomy of plantigrades, unguligrades, and digitigrades. Digitigrade and unguligrade animals have relatively long carpals and [[Biology:Tarsus (skeleton)|tarsals]], and the bones which correspond to the human ankle are thus set much higher in the limb than in a human. In a digitigrade animal, this effectively lengthens the foot, so much so that what are often thought of as a digitigrade animal's "hands" and "feet" correspond to only the human fingers or toes.  Digitigrade locomotion is responsible for the distinctive hooked shape of dog legs.

Plantigrade animals, such as humans, normally walk with the soles of their feet on the ground.  Unguligrade animals, such as horses<!--odd-toed ungulates--> and cattle<!--even-toed ungulates-->, walk only on the distal-most tips of their digits.  Digitigrade animals walk on their distal and intermediate phalanges; more than one segment of the digit makes contact with the ground, either directly (as in birds) or via paw-pads (as in dogs and cats).

==Examples==
[[Image:WolfSkelLyd1.png|thumb|Skeleton of a wolf, showing a typical digitigrade arrangement of leg and foot bones]]
* [[Biology:Mesonychidae|Mesonychidae]]
* Dinosaurs (digitigrade and semi-digitigrade)
** Birds (except for loons and grebes which are plantigrade)
* [[Biology:Suina|Suina]] (semi-digitigrade)
* [[Biology:Hippopotamidae|Hippopotamidae]] (semi-digitigrade)
* ''[[Biology:Pakicetus|Pakicetus]]''
* ''[[Biology:Indohyus|Indohyus]]''
* [[Biology:Thylacine|Thylacine]] 
* [[Biology:Felidae|Felidae]]
* [[Biology:Hyena|Hyena]]s
* Mongooses
* [[Biology:Canidae|Canidae]]
* Elephants (semi-digitigrade)<ref>{{cite web|url=http://www.wildlifeinformation.org/Subdirectories_for_Search2/SampleSpecies/Elephas_maximus/03EleMaxAMLegs.html|archive-url=https://web.archive.org/web/20071214152113/http://www.wildlifeinformation.org/Subdirectories_for_Search2/SampleSpecies/Elephas_maximus/03EleMaxAMLegs.html|archive-date=December 14, 2007|title=APPEARANCE/ MORPHOLOGY: LEGS, SPINE AND TRACKS with literature reports for the Asian Elephant - Elephas maximus (editorial comment)|website=wildlifeinformation.org|url-status=dead}}</ref>
* Capybaras (semi-digitigrade)
* ''[[Biology:Trucidocynodon|Trucidocynodon]]'' (semi-digitigrade at least in the forelimbs)

==References==
{{reflist}}

== External links ==
* {{cite web|url=http://www.cvm.uiuc.edu/petcolumns/showarticle.cfm?id=118|title=Yes, the Shin Bone Is Connected to the Ankle Bone|archive-url=https://web.archive.org/web/20070203151319/http://www.cvm.uiuc.edu/petcolumns/showarticle.cfm?id=118|archive-date=February 3, 2007|website=cvm.uiuc.edu|url-status=dead}}

{{locomotion}}

[[Category:Terrestrial locomotion]]

{{Sourceattribution|Digitigrade}}