Ancient ‘demon ducks’ may have been undone by their slow growth
Sciencenews.org: Giant flightless birds called mihirungs were the biggest birds to ever stride across what is now Australia. The animals, which weighed up to hundreds of kilograms, died out about 40,000 years ago. Now researchers might have a better idea why.
The birds may have grown and reproduced too slowly to withstand pressures from humans’ arrival on the continent, researchers report August 17 in the Anatomical Record.
Mihirungs are sometimes called “demon ducks” because of their great size and close evolutionary relationship with present-day waterfowl and game birds. The flightless, plant-eating birds lived for more than 20 million years.
Over that time, some species evolved into titans. Take Stirton’s thunderbird (Dromornis stirtoni). It lived about 7 million years ago, stood 3 meters tall and could exceed 500 kilograms in weight, making it the largest-known mihirung and a contender for the largest bird ever to live.
Most research on mihirungs has been on their anatomy and evolutionary relationships with living birds. Little is known about the animals’ biology, such as how long they took to grow and mature, says Anusuya Chinsamy-Turan, a paleobiologist at the University of Cape Town in South Africa. So Chinsamy-Turan and colleagues at Flinders University in Adelaide, Australia took samples from 20 fossilized leg bones of D. stirtoni, from animals of varying life stages.
These images were able to resolve meter-scale features – information that will aid in planning lunar exploration, the researchers said.
The photodetector introduced in their recent paper is based on this newly identified, active material.
“When light is absorbed by the perovskite active layer, the photogenerated electrons and holes are extracted through electron and hole transport layers,” said coauthor Maral Vafaie. “To achieve fast response times, these charge carriers must move rapidly across the devices, including the transport layers. Nickel oxide (NiOx) is characterized by high crystallinity and mobility, making it an ideal option for hole transport layer (HTL).”
“I wouldn’t bet my firstborn because I love him too much. But I would bet a nice vacation.”
The JWST data also showed an extra bit of absorption at wavelengths close to those absorbed by carbon dioxide. “It’s a mystery molecule,” says astronomer Natalie Batalha of the University of California, Santa Cruz, who led the team behind the observation.
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