We are delighted to share with you a guest article from the Saola Foundation:
History Channel’s Mysteries Unearthed feature on R. J. Timmins’s discovery of the so-called ‘Laotian Rock Rat’
A rebuttal by R. J. Timmins
Kha-nyou Laonastes aenigmamus – An ancient enigma with an identity crisis
A recent spotlight by the History Channel on the Kha-nyou, a largely unknown endemic species of the Annamite Mountains Bioregion, brought much needed global interest to this unusual species and to the irreplaceable ecosystem it inhabits. However, we are compelled to raise a significant rebuttal to the History Channel’s unfortunate use of the name ‘Laotian Rock Rat’, a modern-day case of mistaken identity for this fantastic creature. The Kha-nyou, an ancient representative of the Order Rodentia, is many things, but it is NOT a rat!
I first came across the Kha-nyou on the 4th of February 1996, during a morning visit to a fresh food market in central Lao PDR, where I’d gone especially to see what wild animals local inhabitants were hunting and selling. Within a matter of moments, and after a quick examination of the two Kha-nyou carcasses on the ground in front of me, I knew I was looking at an undescribed species to science. What I didn’t realise, however, was just how extraordinary, from a scientific perspective, the discovery of the Kha-nyou was. But standing in the morning market in early February, I at first wondered whether this creature could be allied to squirrel taxa in East Asia or the Sundas with which I was unfamiliar.
Author visiting a market in Lao PDR
The Kha-nyou is about 26 cm in head and body length – a size very similar to an Eastern Grey Squirrel Sciurus carolinensis, for those familiar – with short limbs, a densely-haired tail only about half the length of its head and body combined, and a long head with extremely long whiskers. It is various shades of grey in colour, with a ‘mane’ of dark hair from its nape along the dorsum of its neck. The Kha-nyou lives in the limestone karst landscapes of central Lao and Vietnam, is nocturnal and forages over rock and ground, but apparently does not climb in vegetation, and rests, and presumably ‘nests’, in holes and crevices within the limestone. Captive animals are generally docile and placid.
To state my challenge to the History Channel’s piece head-on, the Kha-nyou is not a ‘rat’, and doesn’t have anything in common with the ‘rat family’ other than being, like a squirrel, porcupine, or chinchilla, a member of the Order Rodentia. I was horrified to have this name attributed to me.
You can’t really appreciate the ‘enigma’ in this species’s scientific name, Laonastes aenigmamus, without taking a deep dive into the taxonomic lineage. With an ancestral position within the Order Rodentia, the Kha-nyou’s closest living relatives are thought to be the African gundis of the Family Ctenodactylidae, which together are ancestral ‘basal’ members of the Suborder Hystricomorpha. This Suborder includes the likes of porcupines, chinchillas, and capybaras amongst others. Importantly, the rats, mice, and squirrels are in completely different suborders. The Kha-nyou is now recognised as likely to be the sole living representative of the Family Diatomyidae, otherwise only known from fossils from Eastern Europe, South, Southeast, and East Asia, spanning the last c. 11–33 million years. The Kha-nyou is remarkably similar to the fossil species Diatomys shantungensis, known from the mid Miocene (c. 11 million years ago) of China, and the two are likely to be very closely related; however, they are still considered different species in different genera. The c. 11 million-year gap in the fossil record from the Miocene to the present, along with the discovery of fossils prior to a living animal, has earned the Kha-nyou the designation of a ‘Lazarus’ taxon. Intriguingly, genetic studies suggest Kha-nyous might actually represent several different morphologically near-identical species, some of which potentially diverged on their separate evolutionary paths millions of years ago!
Kha-nyou drawing by author
The Kha-nyou shares a remarkable trait with a number of other endemic and near-endemic species of the Annamite Mountains Bioregion, as a living descendent, little changed for more than 10 million years, of the presumed former Annamites Miocene fauna. Evolution, contrary to common belief, has no direction or goal, and like other species in the Annamites Bioregion, e.g. the Annamite Striped Rabbit, Saola, and Owston’s Civet, the Kha-nyou seems likely not to have changed much over the last 10+ million years, most likely because of environmental stability in the Annamite Bioregion over the same time period. As the saying goes, ‘if it ain’t broke, don’t fix it’ – in other words, why would change happen if there is no pressure to adapt?
Of course, humans have likely known of the existence of Kha-nyous for 70,000 years or more, and before that our Homo ancestors may have known them for a million years. Limited evidence suggests that, from a population perspective and relatively speaking, the Kha-nyou is not facing a high risk of extinction, and for this reason is listed as Least Concern on the IUCN Red List. This prognosis is largely a consequence of the habitat it calls home, jagged rocky limestone karst landscapes that do not have many alternative uses from a human perspective and are also difficult for human hunters to penetrate. Kha-nyou habitat is relatively impervious to drastic large-scale change; small areas are utilised for cement production and other forms of mining, but these represent a very small proportion of the total. Nevertheless, Kha-nyous are likely to have been exploited as a food source for a very long time, and that continues to this day. Kha-nyous are typically caught using traditional wooden and / or bamboo traps. As a relatively small nocturnal animal with no known value beyond its meat value, still large areas of limestone karst remaining, and no clear evidence of strongly declining populations, it is hopefully a species we do not need to worry too much about in the near term (but of course we’ll be keeping an eye on them).
In summary, History Channel, we commend you for bringing much needed attention to this overlooked region, a living museum of the former Miocene and earlier biodiversity, and in need of urgent action to prevent further unrecoverable loss of biodiversity. We respectfully challenge the use of the name ‘Laotian Rock Rat’ and advocate instead for the local name, ‘Kha-nyou’, which has served this enigmatic creature perfectly for perhaps thousands of years. And, if I and the Saola Foundation have anything to do with it, this name will do just fine for many, many more years to come.
Recent Comments