A groundbreaking study of 2,000 ancient fossils reveals that felids - the cat family - have historically been much better at surviving than the "canid" dog clan², and often at the latter's expense.

 

The research finds that cats have played a significant role in making 40 dog species extinct, outcompeting them for scarce food supplies because they are generally more effective hunters. But researchers found no evidence that dogs have wiped out a single cat species.

 

The dog family - which includes the wolves from which today's domesticated³ dogs are descended⁴ - originated in North America about 40 million years ago and reached a maximum diversity around 20 million years later, when there were more than 30 species on the continent. At that point, the cat family arrived from Asia.

 

"The arrival of cats to North America had a deadly impact on the diversity of the dog family. We usually expect changes in climate to play the overwhelming role in the evolution of species. Instead, competition among different carnivore species proved to be even more important for the dogs," said the report's lead author, Dr Daniele Silvestro, of the University of Lausanne in Switzerland.

 

The influx⁵ of cats prompted a period of dramatic decline among the dog clan. This has left North America with just nine species of wild dog today, comprising different variations of wolves and foxes, according to the fossil analysis published in the journal PNAS.

 

Dr Silvestro says it is unclear exactly why, when times were tough, the cats were able to see off dogs so comprehensively. But he believed it could be something to do with the retractable⁶ claws that ancient cats have passed down to their domesticated descendants, but which dogs don't have.

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