In modern times, cats are the most energy efficient hunting mammals. They use less energy per kilogram of prey they catch than any other warm blooded hunter. In the past, this has also been the case. The infamous saber-toothed cat was not one but many different cats. Evolution produced this ultimate predator time and time again through completely unrelated species.
It appears that several of the times sabre cats have appeared, they have been so successful at taking down prey that it gradually wiped out its food source which over time lead to its own extinction. By the time this happened, many of these sabre-toothed cats had caused the extinction of over 50% of the surrounding large prey animals. At other times, it has become so specialised that it has been unable to adapt if its environment changed through natural means. The ultimate mammal apex predator, the saber-toothed cat was so successful and efficient at hunting that nature has reproduced the design, with minor variations, over ten separate times throughout history.
Nimravus (33 – 26 million years ago)
Nimravus means “”. There were at least six different species in the Nimravinus genus, all of whom lived in North America between 33 and 26 million years ago. Nimravus was 1.2m long and weighed 30kg, being slender and agile. It had two 12cm long curved conical teeth protruding from its upper jaw. Nimravus would sink these into its prey, cutting blood vessels and causing slow death from bleeding. If the neck was attacked, the major arteries to the brain would be severed and cause death in minutes. This hunting method was relatively efficient and successful, allowing Nimravus to take down prey animals much larger than itself. All subsequent saber-toothed cats evolved independently of nimravus, and were unrelated, being in different genera.
eusmilus (305 – 28 million years ago)
Eusmilus is the oldest known saber-toothed cat. Its three species lived from 38 million years ago in Europe and the Americas. Two of the eusmilus species were similar in size to modern leopards, weighing 70kg and growing up to 2.5m long. The other species was about the size of a domestic cat, but could take down prey five times its size such as deer. The sabre teeth of this diminutive cat were 10cm long, longer than modern lion canines. The inner edge of these curved teeth was sharp and serrated, making it a formidable weapon for slicing its prey. Eusmilus was unusual in that, despite its large canines, it had far fewer teeth than other cats.
Thylacosmilus (10 – 1.8 million years ago)