Meet the ancient bird that had tears longer than its lower legs. Scientists have discovered a bird's foot from 99 million years ago preserved in amber that had a hyper-longed third toe. The study, published in the journal Current Biology on July 11, suggests that this bird might have used the toes to chop food out of tree cars. This is the first time such a foot structure has been observed in birds, either extinct or alive.
"I was very surprised when I saw the yellow," says first author Lida Xing of China's University Earth Sciences (Beijing). "It shows that old birds were very different than we thought. They had developed many different functions to adapt to their environments."
To study fossil fossil times, Xing and his colleagues scanned the yellow with micro-CT and created a 3D reconstruction of the foot. They found that the bird's third toe, measuring 9.8 millimeters, is 41
The bird was fossilized in yellow 99 million years ago. (Lida Xing / Current biology )
The researchers are called Elektorornis chenguangi. Elektorornis means "yellow bird" and it belongs to a group of extinct birds called Enantiornithes, the most abundant type of bird known from the Mesozoic era. It is believed that Enantiornithines were eradicated during the Cretaceous-Paleogen extermination event about 66 million years ago along with dinosaurs. They have no living descendants.
Based on the fossil, the team estimates that Elektorornis was smaller than a sparrow, and it was arboreal, which meant that it spent most of its time in trees as opposed to on the ground or in water.
"Elongated toes are something you usually see in farm animals, because they must be able to seize these branches and wrap their toes around them," says co-author Jingmai O & # 39; Connor of the Chinese Academy of Sciences. "But this extreme difference in toe lengths, as far as we know, has never seen before."
Tarsal Structure and Integumentary Structures Preserved in Elektorornis Chenguangi HPG-15-2. (Lida Xing / Current biology )
The discovery of the yellow foot that measured 3.5 centimeters long and weighs 5.5 grams was discovered around 2014 in the Hukawng valley in Myanmar . During the Mesozoic era, the valley was full of trees that produced resin, a sticky substance that oozes out of the tree bark. Plants and small animals, such as cucumbers and spiders, are often trapped in the resin and become fossilized with amber after millions of years. Scientists have discovered many extinct animals, including the oldest known bee and a resilient dinosaur neck, in the amber from this valley.
Xing received amber from a local amber dealer who did not know which animal this strange foot belonged to.
"Some traders thought it was a lizard foot, because lizards tend to have long toes," Xing says. "Although I have never seen a bird claw look like this, I know it's a bird. Like most birds, it has four toes, while lizards have five."
It is still unknown why the yellow bird developed so unusual. The only known animal with disproportionate numbers is aye-aye. Aye-aye is a lemur that uses its long middle finger to fish larvae and insects from tree trunks for food. Therefore, the researchers suggest that Elektorornis may have used the toe for the same purpose.
"This is the best guess we have," says Connor. "There is no bird with similar morphology that can be considered a modern analog for this fossil bird. A lot of ancient birds probably did completely different things than living birds. This fossil exposes another ecological niche that these early birds experimented with as they developed. Moving forward, the team hopes to extract the proteins and pigments from some feathers exposed on the surface of yellow. Xing says that such data can help them better understand the bird's adaptation to the environment, for example, if it had camouflage depth.
Top image: Artist impression of the bird with a third toe 41 percent longer than other toes. Source: Zhongda Zhang / Current Biology
The article entitled "Bird with unusually long toes found fossilized in yellow" was first published on Science Daily.
Source: Cell Press. "Bird with unusually long toes found fossilized in amber." Science. Science Daily, July 11, 2019. www.sciencedaily.com/releases/2019/07/190711141407.htm
Lida Xing, Jingmai K. O & # 39; Connor, Luis M. Chiappe, Ryan C. McKellar, Nathan Carroll, Han Hu, Ming Bai, Fuming Lei. A new enantiornitine bird with unusual pedal proportions was found in Amber . Current Biology 2019; DOI: 10,1016 / j.cub.2019.05.077