The second one is nyala, nana, and I think may be an example of the "sexual dimorphism" mentioned, depending on the size!
More and more sightings have been coming to light of "ewes with horns"...but for many decades now! The prevailing theory, after it seems to have been found that the animals have male sex organs, is that they are actually males with female bodies...
The horns can get almost as long as those of normal bulls, but much thinner!
The Nyala (Nyala angasii) is a Southern African antelope. It is a spiral-horned dense-forest antelope that is uncomfortable in open spaces and is most often seen at water holes. Nyalas live alone or in small family groups of up to 10 individuals.
The male stands up to 110 cm (3.5 feet), the female is up to 90 cm (3 feet) tall. The male has loosely spiraled horns and a long fringe on throat and underparts; the female has no horns and no noticeable fringe. The male is dark brown, white on the face and neck, with vertical white stripes on the body. The female is reddish brown with white vertical striping.
The rare Mountain Nyala (Tragelaphus buxtoni) is limited to central Ethiopia. While superficially similar to the lowland Nyala, it is now considered more closely related to the kudu.
The name "Nyala" is the Swahili name for this antelope, which itself comes from the Zulu "Inyala". The Latin name comes from "tragos" (he-goat), "elaphos" (deer), and George French Angas of South Australia.
Nyala taxonomy and evolution
The Nyala is the second taxa to branch off of the Spiral-Horned Antelope family tree just after the Lesser Kudu. Fossil evidence suggests that the Nyala has been a separate species since the end of the Miocene (5.8 million years ago). Genetic evidence suggests that the proto-Nyala had some early hybridization with the proto-Lesser Kudu, but the two have remained separate long after this crossing.
As the Nyala line has remained separate for a considerable amount of time (over 5 million years), it has now been placed in its own monotypic genus Nyala. Nyala, like Ammelaphus (Lesser Kudu), was proposed by Edmund Heller in 1912, but not widely recognized, and was only reestablished as a valid genus in 2011 by Peter Grubb and Colin Groves.
There is no geographic variation for the genus Nyala, and thus no additional species or subspecies.
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