They belong to the evolutionary lineage that would give rise to the first mammals 50 million years later. They were warm-blooded animals like modern mammals, but, unlike most of them, they laid eggs.
Before dinosaurs walked the Earth and tens of millions of years before the first mammals appeared, distant mammal relatives with long, serrated canine teeth were the dominant carnivores on land.
Health authorities have called for increased monitoring of US farm workers at risk of catching H5N1, after genetic data confirmed the first instance of the virus jumping from mammals to humans.
Before dinosaurs walked the Earth and tens of millions of years before the first mammals appeared, distant mammal relatives with long, serrated canine teeth were the dominant carnivores on land.