Paleontologists have found the remains of a pelagornithid bird that lived 62 million years ago (early Paleocene epoch) in New Zealand.
Dubbed Protodontopteryx ruthae, the ancient seabird belongs to Pelagornithidae, an ancient family of bony-toothed birds.
These seafaring birds were previously known from late Paleocene to Pliocene fossil sites and some species reached wingspans up to 6.4 m (21 feet).
Protodontopteryx ruthae is the oldest, but smallest member in the family.
It was only the size of an average gull and, like other pelagornithids, had bony, tooth-like projections on the edge of its beak.
The partial skeleton of Protodontopteryx ruthae was found by amateur paleontologist Leigh Love at the Waipara Greensand fossil site in 2018.
“The age of the fossilized bones suggests pelagornithids evolved in the Southern Hemisphere,” said Dr. Paul Scofield, a curator at Canterbury Museum and the senior author of a paper published in the journal Papers in Palaeontology.
“While this bird was relatively small, the impact of its discovery is hugely significant in our understanding of this family.”
“Until we found this skeleton, all the really old pelagornithids had been found in the Northern Hemisphere, so everyone thought they’d evolved up there.”
“New Zealand was a very different place when Protodontopteryx ruthae were in the skies. It had a tropical climate — the sea temperature was about 25 degrees Celsius (77 degrees Fahrenheit) so we had corals and giant turtles.”
“The discovery of Protodontopteryx ruthae was truly amazing and unexpected,” said co-author Dr. Gerald Mayr, a researcher with the Senckenberg Research Institute and Natural History Museum.
“Not only is the fossil one of the most complete specimens of a pseudotoothed bird, but it also shows a number of unexpected skeletal features that contribute to a better understanding of the evolution of these enigmatic birds.”
The skeleton of Protodontopteryx ruthae suggests it was less suited for long-distance soaring than later pelagornithids and probably covered much shorter ranges.
Its short, broad pseudoteeth were likely designed for catching fish. Later species had needle-like pseudoteeth which were likely used to catch soft-bodied prey like squid.
“Because Protodontopteryx ruthae was less adapted to sustained soaring than other known pelagornithids, we can now say that pseudoteeth evolved before these birds became highly specialized gliders,” said co-author Dr. Vanesa De Pietri, a curator at Canterbury Museum.
Gerald Mayr et al. Oldest, smallest and phylogenetically most basal pelagornithid, from the early Paleocene of New Zealand, sheds light on the evolutionary history of the largest flying birds. Papers in Palaeontology, published online September 17, 2019; doi: 10.1002/spp2.1284