The yellow-striped chevrotain (Moschiola kathygre), also known as the wet-zone mouse-deer, is a fascinating and exceptionally primitive hoofed mammal that was only recognized by scientists as a distinct species in 2005. Before this discovery, it was lumped together with its dry-zone relative, the spotted chevrotain.
An incredible fact about the yellow-striped chevrotain is its evolutionary status as a "living fossil." It belongs to an ancient family of ruminants (animals with specialized multi-chambered stomachs) that bridges the evolutionary gap between non-ruminants like pigs and modern ruminants like true deer. Because they branched off so early, adult males do not grow antlers; instead, they have evolved elongated, razor-sharp upper canine teeth that extend downward past their lips like miniature daggers. Males use these sharp canine tusks to fiercely slash and stab at rivals when defending territory.