Researchers digging in a cave in New Zealand’s North Island have discovered a treasure trove of ancient bird fossils dating back one million years. The findings, published in Alcheringa: An Australasian Journal of Palaeontology, reveal a previously undiscovered group of ancient avians in Aotearoa. One of the fossils identified includes a predecessor of the distinctive flightless parrot, the kākāpō.
The fossils were unearthed at Moa Eggshell Cave, near the village of Waitomo on New Zealand’s North Island, and analyzed by paleontologists from Flinders University and Canterbury Museum.
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Uncovering Ancient Species in New Zealand
The dig revealed fossils from 12 ancient birds and four frog species. Trevor Worthy, a paleontologist at Flinders University, said that some of the birds were previously unknown members of New Zealand’s fossil record.
“This remarkable find suggests our ancient forests were once home to a diverse group of birds that did not survive the next million years,” he commented in a statement.
Several of the species have died out over the intervening years, likely due to shifts in climate or massive volcanic eruptions across the islands.
The research isn’t the first major fossil find in New Zealand, but it provides insight into a poorly understood time period, said Paul Scofield, senior curator of natural history at Canterbury Museum.
“From our excavations at St Bathans in Central Otago over many years, we have a snapshot of life in Aotearoa between 20 [million] and 16 million years ago. These new findings cast light on the 15 million-year period from then to 1 million years ago, which is largely absent from New Zealand’s fossil record,” said Scofield in a statement.
An Ancient Ancestor of the Kākāpō
One of the newly identified cave species is Strigops insulaborealis, an ancestor of the kākāpō parrot. Unlike its extant descendant, which is flightless and climbs trees with its strong legs, analysis of S. insulaborealis suggests it could have flown, though further research will be needed to confirm this.
Also found were an ancient counterpart of the distinctive takahē, a flightless swamphen native to New Zealand, and an ancient pigeon species. The researchers believe that volcanic activity and climate shifts altered the islands’ forests and scrublands, forcing a hard reset for native birds.
“We believe this was a major driver for the evolutionary diversification of birds and other fauna in the North Island,” said Scofield.
Finding New Zealand’s Missing Volume
The fossils were recovered from a sandwich of ancient volcanic ash. The ages of these two ash layers — one from an eruption 1.55 million years ago and the other from an eruption 1 million years ago — allowed the fossils to be accurately dated.
The volcanologists in the study team analyzed the ash and suggested the more recent eruption was a massive event that would have buried most of the North Island in deep ash. The presence of the older ash layer in the Moa Eggshell Cave implies it is the oldest cave on the island.
“For decades, the extinction of New Zealand’s birds was viewed primarily through the lens of human arrival 750 years ago. This study proves that natural forces like super-volcanoes and dramatic climate shifts were already sculpting the unique identity of our wildlife over a million years ago,” said Worthy.
“This wasn’t a missing chapter in New Zealand’s ancient history; it was a missing volume,” said Scofield.
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Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from a recent study published in Alcheringa: An Australasian Journal of Palaeontology: The first Early Pleistocene (ca 1 Ma) fossil terrestrial vertebrate fauna from a cave in New Zealand reveals substantial avifaunal turnover in the last million years
