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BirdNote®
The Wonderchicken!
Written by Mark Bramhill and Bob Sundstrom
This is BirdNote.
In 2018, when paleontologist Daniel Field was researching the evolution of birds, he examined some previously overlooked fossil specimens from the end of the Age of Dinosaurs.
Daniel Field: The fossils were discovered by a novice fossil collector from the Netherlands named Maarten van Dinther in the year 2000. Basically, we have a very nice rock with two bones sticking out, but they look like bird bones. , so we want to try to peek inside the stone to see if there is anything inside.
He put aside his chisel for this delicate work. Daniel and his team used micro-CT scanning, which is like a high-energy CAT scan, allowing them to image the encased fossils in detail without the risk of damaging them.
Daniel Field: When we did that with this particular specimen, we were really amazed to find completely encased in the rock an almost complete, three-dimensionally preserved skull of a small bird from the end of the Age of Dinosaurs. And it totally blew our minds because a complete skull of an early modern bird from the end of the age of dinosaurs had never been seen before.
[Music]
Daniel Field: All the giant dinosaurs disappeared about 66.02 million years ago when a massive asteroid hit the earth and caused one of the largest mass extinction events in the history of our planet. And this fossil is somewhere around 66.7 million years old, which means that this animal was alive in what you might think of as a geological blink of an eye before the asteroid impact. It gives us a stunning lens into what birds were like before the asteroid impact wiped out the giant dinosaurs.
This is the earliest known fossil record of a modern bird — distinct from the bird-like dinosaurs — with features such as a toothless beak and fused leg bones. The skull is small, less than 2 inches long, so it is not a large bird. And comparing the fossil to modern birds reveals something really interesting:
Daniel Field: The front of the skull looks a lot like the skull of a small chicken-like bird like a quail. Whereas the back of the skull looks very similar to what you would see on a small bird like a duck, something like a Green-winged Teal, for example. And the skull is coming together in a way we’ve never seen before and that’s fascinating because currently, the closest living relative of the chicken group is the duck group. We think the fossil is close to the last common ancestor of a really important living group of birds.
And so with this incredible turducken of a fossil, Daniel and his team named it: the Wonderchicken. (They gave it the more formal name of Asteriornis maastrichtensis [pron. ahs-teer-ee-OR-nuhs mah-strik-TEN-sus]but, c’mon — Wonderchicken!!!) And Wonderchicken helps answer why those early modern birds survived the cataclysmic asteroid event.
Daniel Field: After the asteroid impact, global forests were destroyed by wildfires from the heated ejecta from the asteroid impact rating back, worldwide.
And from fossils, we know that the Wonderchicken had long, narrow legs. It was found on what was, 67 million years ago, a Bahamas-like tropical white sand beach. That means it may not need forests to survive.
Daniel Field: So it makes a lot of sense to reconstruct the magnificent chicken as a relatively small-bodied, long-legged coastal dweller, something like a modern-day sandpiper. That could prove this sort of idea that ground-dwelling birds might be at an advantage compared to their tree-dwelling relatives that disappeared when the asteroid hit.
This elusive, quail-sized bird that walked along the Cretaceous coastline has given us a richer understanding of the origins of birds as we know them. And for that, it truly earns the title: Wonderchicken.
For BirdNote, I’m Mark Bramhill.
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Senior Producer: John Kessler
Content Director: Allison Wilson
Producer: Mark Bramhill
Associate Producer: Ellen Blackstone
Managing Producer: Conor Gearin
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Domestic Chicken (Red Junglefowl) ML 110920 recorded by TG Sander, and Mallard ML 93506381 recorded by B. Walker.
The BirdNote theme was composed and played by Nancy Rumbel and John Kessler.
© 2021 BirdNote December 2021 Narrator: Mark Bramhill
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Reference: https://www.nature.com/articles/s41586-020-2096-0
ID# wonderchicken-01-2021-12-09 wonderchicken-01
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