Three Sao la (Vu Quang ox), one of the world's rarest mammals, were observed in Lam Thuy District in the central province of Quang Binh, said a representative of the Dong Chau protective forest Management Board on January 24.

A Sao la (Pseudoryx nghetinhensis). Sao la is first observed in the late 1990s. (Filed photo)

The Sao la, a type of forest-dwelling bovine is listed as critically endangered on the Red List of the International Union of Nature and Natural Resources (IUCN) and Vietnam.

Forest rangers who made the discovery said there were two large animals and a baby.

Due to its relatively inaccessible habitat, little is known about the elusive long-horned mammal, which was first observed in the late1990s.

The first trace of the specie’s existence was a pair of horns found by Vietnamese zoologist Do Tuoc near the Vu Quang Nature Reserve in Ha Tinh Province. He was accompanying a World Wildlife Fund research team at the time.

The animal was then named Pseudoryx nghetinhensis.

Nghetinhensis refers to the two north-central provinces of Nghe An and Ha Tinh.

In 1996, many traces of the rare animal were reported in several Thua Thien-Hue Province districts.

In 2002, evidence of sao la was also found in Le Thuy District, Quang Binh Province.