The study's authors emphasize the need for an international agency or panel that can assess and synthesize data on pandemic prevention, preparedness and response and collect metrics on intactness of landscapes, ecological integrity and biodiversity.

The returned pieces will be examined by specialists "to confirm their authenticity and intactness," authorities said.

“As transport and infrastructure hubs become more developed, there is a severe risk of losing that wildness, that intactness, that integrity,” he said.

The services include provision of clean water and air, food, timber, pollination, fertile soil, erosion control, and coastal protection, as well as a measure of habitat intactness.

“There is no correlation between the age and intactness of a fossil skeleton,” Kirk Johnson explained, in an e-mail.