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The Caprinae is one of the most successful bovid
subfamilies, with 35 currently recognized species found in mountainous
regions across Europe, Asia, Africa, and North America. Their success is
due to a generalized form with specializations for montane habitats, a
combination which confers flexibility within the alpine biome. The
Caprinae tend to be medium-sized ungulates, with a compact form, thick legs,
a sure-footed nature, and tolerance of extremes in temperature which
occur in mountainous environments.
The Caprinae diverged from the other Aegodontia in the early Miocene, appearing
in the Eurasian fossil record 18-15 million years ago. The Caprinae
were excluded from the Eurasian lowland habitats by the dominant
Cervidae (deer), but were able to fill
a specific niche in alpine habitats. The prevalence of mountains
throughout Europe and Asia provided the perfect setting for the rapid
evolution of the Caprinae during the late Miocene. The lack of
alpine habitat in Africa (and the abundance of mountains in Eurasia) explains
why this is the only bovid subfamily to be significantly more diverse
in Eurasia than Africa.
Despite being nested deeply within the Aegodontia, the Caprinae is the only
subfamily which is not seen as containing "antelope" (with the exception
of the chiru or Tibetan antelope, Pantholops hodgsonii); in an attempt
to correct this, some authors chose to describe the members of this subfamily
as "goat antelope".
There are four currently recognized tribes in this subfamily:
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Pantholopini - chiru
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Ovibovini - musk ox and takin
-
Rupicaprini - gorals, serows, and chamois
-
Caprini - sheep, goats, and tahrs
The position of the chiru (Pantholops hodgsonii) has only recently
been resolved. Formerly, this species was thought to ally closely with
the saiga antelopes (Saiga sp.) in the tribe Saigini, forming a putative
link between gazelles (Antilopinae) and goats
(Caprinae). However, molecular testing has determined that Saiga
is distinctly antelopine, while Pantholops is distinctly goat-like.
Some authors consider the chiru to be distinct enough to warrant placing
it in a separate subfamily, the Pantholopinae.
Generally both sexes of the Caprinae bear horns (except in the tribe
Pantholopini, where they are only found in males). There is extreme
sexual dimorphism in the Caprini - this is especially prevalent in the size
and shape of the horns. The other tribes show very few differences between
the sexes with regard to size, coloration, and horn size. |
