An ancient bird with an insanely long toe has been found preserved in 99 million-year-old Burmese amber and this has led to the revelation of a new species of an ancient bird. Newly named as Elektorornis chenguangi, it is a bird distinct from all others because of its hind limb. The third digit on its foot is claimed by researchers to be twice the size of its lower leg.
The palaeontologist Lida Xing from the China University of Geosciences in Beijing was surprised to see Amber and said that the ancient birds were much more diverse than we thought and have evolved different features to adapt to their environments. The study has been published in Current Biology.
This fossil was discovered in 2014 in Hukawng Valley in Myanmar and the origins of the foot remained a mystery until it fell into the hands of the palaeontologists. It was seen as a lizard foot as they tend to have long toes says Xing who was contacted by a museum curator about the specimen.
The toe is 9.8 millimetres long and is thought to have belonged to a small arboreal bird, smaller than a sparrow that went extinct close to 66 million years ago along with the dinosaurs. After researching and scanning the amber and reconstructing, it was found that the third toe was 41% longer than the second toe and 20% longer than the bone in its lower leg. There were no matches found after comparing it with 20 extinct birds and 62 living birds. The proportion was not found in any other animal.
The claws could be used to grip branches and grasp surfaces better. The only known animal with disproportionally long digits is the aye-aye which uses fingers for foraging hard places like tree trunks that are home to juicy larvae and insects.
With the absence of any other long toes, it cannot be made sure what roles the appendage played as admitted by the author and was probably advantageous in some ecological niche that is no longer being exploited. It could be representing a feeding similar to aye-aye or may have facilitated greater arboreal functions.
These elongated toes are also observed in tree-climbing lizards. The soft tissue on the bird’s foot has a filamentous structure and the size which the researchers could not match with other examples. The structure is more robust and longer at the base of the big tow and might represent sensitive hair capable of feeling potential food. The tactile bristles on the feet of Elektornis might have aided in prey detection with the elongated third digit producing unique foraging structure.