A remarkable collection of fossils found in a cave on New Zealand’s North Island has provided scientists with their initial insight into ancient forest species that existed over a million years ago.
These fossils include 12 ancient bird species and four frog species, among which are several previously unidentified bird species. Collectively, these fossils illustrate a world from the past that appears significantly different from the present.
This discovery also addresses a crucial gap in the scientific comprehension of the extinction patterns that occurred prior to human settlement in New Zealand 750 years ago.
The research team published their findings in the journal Alcheringa: An Australasian Journal of Palaeontology in January.
“This represents a newly identified avifauna for New Zealand, which was supplanted by the one encountered by humans a million years later,” stated Trevor Worthy, the lead author of the study and an associate professor at Flinders University. “This extraordinary discovery indicates that our ancient forests were once inhabited by a diverse array of birds that did not endure the subsequent million years.”
The fossils were discovered between two layers of volcanic ash preserved within the cave, each corresponding to a significant eruption, the first occurring 1.55 million years ago and the second 1 million years ago.
Many of the species represented in the fossils had already become extinct by the time humans arrived on the island. By extrapolating from their findings, the research team estimated that between 33 and 50 percent of all species on the island went extinct during the million years leading up to human arrival in New Zealand, likely due to rapid climate changes and catastrophic volcanic eruptions, according to Paul Scofield, co-author of the study and senior curator of natural history at Canterbury Museum.
Worthy stated, “For many years, the extinction of New Zealand’s avian species was primarily interpreted through the perspective of human arrival 750 years ago. This research demonstrates that natural phenomena such as super-volcanoes and significant climate changes were already shaping the distinctive characteristics of our wildlife over a million years ago.”
Among the discoveries, scientists are particularly thrilled about the identification of a new parrot species, Strigops insulaborealis, an ancient relative of the well-known Kākāpō, a large, flightless parrot recognized for its size. The research team posits that this ancestor may have had the capability of flight. Upon examining the fossil, they observed that the ancient bird exhibited weaker legs compared to its modern counterpart, suggesting that it was not as adept at climbing as the contemporary Kākāpō. Nevertheless, the team emphasized that further investigation is required to ascertain whether this ancient bird was capable of flight.
Additionally, the researchers discovered an ancestor of the current Takahe, which paves the way for more studies on that species. Fossils of an extinct pigeon species, closely related to the Australian bronzewing pigeons, also generated excitement among experts.
“The changing forest and shrubland environments necessitated a reset of the avian populations,” Scofield remarked. “We believe this was a significant factor driving the evolutionary diversification of birds and other fauna in the North Island.”
Scofield noted that earlier excavations indicated life in New Zealand between 20 and 16 million years ago, while the recent findings provide the first evidence of life spanning from 15 million years ago to one million years ago. “This was not merely a missing chapter in New Zealand’s ancient narrative,” Scofield stated, “it was a missing volume.”
