Almost all of us have heard of Sabretooths, thanks to the animated ‘Ice Age’ franchise. The first movie, released in 2002, happens to be a favourite of mine. Sid (the Ground Sloth), Manny (the Woolly Mammoth) and Diego (the Sabretooth) had some of the best lines, combining humour and sarcasm in equal measure. But this wasn’t the first time I had run into long-extinct felids with wicked-looking fangs. Being a fan of all things creepy-crawly or beastly, I spent a lot of time watching natural history documentaries. One of which happened to be BBC’s  ‘The Velvet Claw’. The series, seven-episodes long, traced the evolution of mammalian carnivores.

Among these were the fantastic Sabretooths. Their ferocious appearance and  intimidating physique (heightened by a stubby tail) put lions in the shade. ‘The Velvet Claw’ Sabretooths belonged to the genus Smilodon. There were three species – Smilodon populator (South American), Smilodon fatalis and Smilodon gracilis (both North American). The former was an enormous felid, among the largest ever, weighing as much as 400 kg. That would make them ambush hunters reliant on stealth rather than speed. Despite their physical resemblance to big cats, they formed a totally separate lineage, the Machairodontinae.

The big cats we see around us (Tigers, Lions, Jaguars and Leopards) belong to the group Pantherinae. The smaller cats (including those which have grown big such as the Puma, Cheetah, Lynx and Caracal) form the group Felinae. The Machairodontinae had separated long back, some 23 million years ago. They produced numerous genera, including Homotherium and Smilodon. While the latter retained the felid body type, the former evolved an unusual appearance, with long forelimbs, short hindlimbs and sloping backs. It is speculated that they ran down prey on open grasslands like modern Hyenas. Homotherium species were comparatively smaller, reaching only 190 kg.

Machairodontinae evolved to exploit the large mammalian herbivores of the Pleistocene. Their size, strength and hide-puncturing fangs were meant for dispatching young Mammoths, Mastodons and Ground Sloths. Once these great creatures disappeared around 11,000 years ago (most probably due to a combination of climate change and human pressure), they too went extinct. However, the Sabretooth design hasn’t vanished altogether. Among the Pantherinae (commonly known as the big cats) are two species that share some of the traits of their long-extinct cousins. I am talking about the Clouded Leopards of tropical Asia (Nepal, India, Bangladesh, Bhutan, China and Southeast Asia). Once upon a time they were even found in Taiwan.

There are two species – Neofelis nebulosa of the mainland, and Neofelis diardi of Sumatra and Borneo. The smallest of the big cats, they have the biggest canines in proportion to body size. A comparison with their cousins, the Tigers, will be helpful. Tigers, standing 110 cm at the shoulders and weighing as much as 300 kg, have canines that can reach a length of 9 cm. No living felid can match that record in absolute terms. Neofelis, a mere 40 cm at the shoulders and 23 kg in weight, have canines 5 cm in length. Another unique feature is their ability to achieve a gape of 100 degrees, way beyond anything seen in living felids. This enables them to take down prey far larger than them.

Unlike the extinct Homotherium and Smilodon, Neofelis are highly arboreal. More so than any other big cat. They can descend tree trunks head first, negotiate branches from below, hang down using their hindlimbs, and hunt down arboreal primates, rodents and birds. All because of a highly flexible, backward-rotating ankle joint. Short legs, large paws and long tails provide balance and grip. Clouded Leopards can hunt on the ground and survive across a range of habitats – dry woodlands, tropical rainforests, mangrove swamps and Himalayan foothills. If these enigmatic cats somehow manage to survive human beings, they might very well give rise to a new lineage of fanged killers.

Image Attribution: The image above, sourced from Wikimedia Commons shows a Clouded Leopard of the mainland (Neofelis nebulosa). It was done by by Joseph Wolf in 1853 as part of the Zoological Society of London‘s publications. Wolf (1820-1899) was a German artist specializing in natural history. He moved to the British Museum and worked with the likes of David Livingstone and Alfred Russell Wallace.