Fossils Show How to Restore Lost Biodiversity

Animal species have come and gone over the years, but a new study has discovered how fossils can be used to restore lost biodiversity.

The key lies in organic materials found in fossil bones, which contain evidence for how ancient ecosystems once functioned, according to the study, published in the Journal of Herpetology. 

Scientists from the University of Florida focused on tropical islands in particular, where many native species have disappeared as a result of human impact. Fossils showing what pre-human conditions may have been like provide vital clues for saving endangered island species and re-establishing native species, according to researchers.

"Our work is particularly relevant to endangered species that are currently living in marginal environments," lead author Alex Hastings said in a statement. "A better understanding of species' natural roles in ecosystems untouched by people might improve their prospects for survival."

Thousands of years ago, the Bahamian island of Abaco boasted a pair of massive carnivore and herbivore species, later to disappear. Both the endangered Cuban Crocodile (Crocodylus rhombifer) and the now-extinct Albury's Tortoise (Chelonoidis alburyorum) once flourished, but today there is no modern terrestrial ecosystem like that of ancient Abaco for these mega-reptiles to inhabit. Small numbers of the Cuban crocodile can be found in Cuba, but aren't nearly as abundant as they could be if they lived in their natural, wider Abaco habitat.

To understand the missing pieces of their ecosystem, scientists analyzed the types of carbon and nitrogen in well-preserved fossil bones from the Cuban Crocodile and Albury's Tortoise, which was unknown to scientists before its 2004 discovery in the Bahamas.

The data reveal the crocodile and tortoise were both terrestrial, showing that reptiles "called the shots" on the island, Hastings said.

The terrestrial nature of these creatures is a great indicator of how biodiversity has changed in the Bahamas and what ideal conditions are needed for these or similar species to return, added co-author David Steadman.

"On islands like Abaco that have always been dominated by reptiles, the flora and fauna are more vulnerable because they have evolved to lead a more laid back, island existence," Steadman explained. "Understanding this is important to designing better approaches to conservation on the island."