Fossil of 99 million-year-old bird with giant toe found in Burma

Nicola Smith
Scientist think the bird may have used its toe to hook grubs out of tree trunks - Zhongda Zhang / Current Biology

The fossilised remains of an ancient 99-million-year-old bird with a freakishly long toe have been discovered in a chunk of amber from Burma. 

Researchers found the third digit of the sparrow-like creature’s foot was 9.8 millimetres long, about 41 percent longer than its second-longest digit, and 20 percent longer than its entire lower leg, reported Science News. 

Palaeontologists are unsure what purpose the extra-long toe served, but it may have helped the cretaceous period bird find food in difficult-to-reach places such as holes in trees. The bird may have been a tree-dweller, also using its extended claw to grasp on to branches. 

The formation of its foot was so unique that a team examining the fossil, led by paleontologist Lida Xing from the China University of Biosciences in Beijing, decided to declare a new species, calling the bird Elektorornis (amber bird) chenguangi. Their findings were published in Current Biology on Thursday.

The New York Times reported that the remains had lain undisturbed in hardened tree resin until amber miners found the fossil in Burma’s Hukawng Valley in 2014. 

It was first presented to Chen Guang, a curator at China’s Hupoge Amber Museum, and initially suspected to be an extinct lizard.  

However, Mr Chen decided to consult Ms Xing who specialises in Cretaceous birds and the tiny creature was discovered to be related to an extinct group of toothed, clawed birds called Enantiornithes, which was bountiful during the Cretaceous period of 145.5 million to 66 million years ago. 

The ancient bird was found fossilized in amber Credit: Lida Xing/PA

“I was very surprised at the time,” Dr Xing told the Times, recalling that the fossil was “undoubtedly the claw of a bird.”

Dr Xing’s team compared the toe size ratios with other known birds starting from the Mesozoic era, which began 252 million years ago, and found that no other species had such a dramatic difference in toe sizes. 

The Elektorornis chenguangi died out with other species in its family along with non-avian dinosaurs at the end of the Cretaceous period.