Excerpt from The Last Unicorn by William deBuys, plus links to reviews, author biography & more

In short order the saola's presence in Laos was confirmed, again by the presence of trophies on hunters' walls — not by live sightings. As more scientists began to probe the Annamite Mountains, a series of stunning additional discoveries ensued. Within years of confirmation of the saola, more new mammals were identified, including several new species of muntjac, or barking deer. The taxonomic validity of one of these, Muntiacus vuquangensis, the large-antlered muntjac, is beyond question; other proposed species are still debated because not much evidence about them is available, and the little that exists fails to fit in neat categories. The effort to solve the riddles of the Annamites' biology continues undiminished to this day; indeed, that is why we are here.

One reason the saola so captured the imagination of scientists is its "phylogenetic distinctiveness." That's a fancy way of saying that the saola has no close relatives in evolutionary or genetic terms. It is not a late-branching twig on the tree of life; it is a stub off a major limb, and it grows close to the trunk. From the large, strange scent glands on either side of its muzzle to the bands of color on its tail, the saola resembles no other animal. Classifying it was a puzzle. Was it an antelope? A goat? It looked more like an Arabian oryx than anything else, hence its genus name, Pseudoryx. Another datum in favor of the antelope hypothesis was its habitat, which was similar to that of the duiker, a small, furtive antelope of African rain forests. DNA analysis of the bone of its horns, however, indicated a greater affinity with wild cattle and suggested that the saola was a very ancient kind of ox that had diverged eons ago, perhaps in Miocene times, from the ancestors of aurochs, bison, and buffalo. In the susequent seesaw between moist and dry environments, the saola's cousins grew ponderous and spread through the region's grasslands, savannas, and dry forests. The saola, meantime, remained physically nimble but environmentally cramped. As the moist evergreen forests on which it depended ultimately retreated to the Annamites, the saola necessarily retreated as well. Today, among the large mammals on Earth, few, if any, possess so small a habitat.

So distant is the saola from the lumbering ruminants with which it shares the greater part of its genes that it seems closer, at least in a metaphorical way, to a creature of myth. In its spirit — or perhaps only in the spirit that the Westerners pursuing it imagine it to have — the saola seems kindred to the fabled unicorn of medieval lore. Like the unicorn, it is as rare as the rarest thing on Earth. It is shy and elusive, hard to find and harder to capture, the same as the unicorn was said to be. Also like the unicorn, it seems to possess an otherworldly disposition, different from that of other beasts. And its horns, up to half a meter long and elegantly tapered, are as beautiful as the unicorn's. When seen in profile, the saola's horns merge into one, and the animal becomes single-horned — a unicorn by perspective. Like that other one-horned beast, it stands close to being the apotheosis of the ineffable, the embodiment of magic in nature. Unlike the unicorn, however, the saola is corporeal. It lives, and it can die.

Excerpted from the book The Last Unicorn by William deBuys. Copyright © 2015 by William deBuys. Reprinted with permission of Little, Brown and Company