A spectacular trove of fossils in a discovered in a cave on New Zealand's North Island has given scientists their first glimpse of ancient forest species that lived there more than a million years ago. The fossils represent 12 ancient bird species and four frog species, including several previously unknown bird species. Taken together, the fossils paint a picture of an ancient world that looks drastically different than it does today. The discovery also fills in an important gap in scientific understanding of the patterns of extinction that preceded human arrival in New Zealand 750 years ago.
The team published a study on the find in Alcheringa: An Australasian Journal of Palaeontology.
“This is a newly recognized avifauna for New Zealand, one that was replaced by the one humans encountered a million years later,” Trevor Worthy, lead study author and associate professor at Flinders University, said in a statement. “This remarkable find suggests our ancient forests were once home to a diverse group of birds that did not survive the next million years.”
The team located the fossils between two layers of volcanic ash preserved in the cave, each from a different major eruption, the first 1.55 million years ago and the second 1 million years ago. Many of the species represented among the fossils had already gone extinct by the time humans arrived on the island. By extrapolation, the research team estimated that between 33 and 50 percent of all species on the island went extinct during the million years before humans arrived in New Zealand, likely thanks to rapid climate shifts and cataclysmic volcanic eruptions, said Paul Scofield, study co-author and Canterbury Museum senior curator of natural history.