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A new species of bird dating to around 68 million years ago has been discovered on the island of Madagascar, and its unusual beak may provide new insight into the evolution of modern birds.
Discovered from a single, nearly complete skull that was fossilized after being buried in muddy debris, Falcatakely is a crow-sized bird with a scythe-shaped beak. It is not at all unusual in modern birds and resembles hornbills and toucans. However, there is a gap of tens of millions of years between these evolving species.
“What’s so amazing is that these lineages converged on this same basic anatomy despite being very far apart,” said Dr Ryan Felice, Senior Lecturer in Human Anatomy at University College London and one of the study’s authors. In fact, this is the first time that such a beak shape has been found on a bird from the Mesozoic era – the era that contains the Cretaceous, Jurassic, and Triassic periods.
Looking under Falcatakely’s skin reveals another unusual feature. Although its face may have the appearance of a modern bird, its underlying bone structure is much more like that of a dinosaur. Modern birds have a beak made mostly of a large bone, called the premaxilla. Ancient birds, like the dinosaur Archeopteryx, had two rather, with a small premaxilla and a large maxilla.
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Thus, Falcatakely developed a modern face shape without a modern facial structure. “Falcatakely can generally resemble any number of modern birds with the skin and beak in place, however, it is the underlying skeletal structure of the face that transforms what we know about the evolutionary anatomy of birds. on his head, ”said Professor Patrick O’Connor, an anatomist at Ohio University.
The team could not directly study the skull. Bird fossils are rare because their skeletons are so fragile that they are usually destroyed rather than fossilized. The specimen is so fragile that they couldn’t even pull it out of the rock. Instead, the team used a high-resolution micro-computed tomography scan to scan the fossil, which they then used to digitally reconstruct it.
“Falcatekely’s discovery underscores that much of Earth’s deep history is still shrouded in mystery,” O’Connor added, “especially in parts of the planet that have been relatively less explored.
“The more we learn about the animals, plants and ecosystems of the Cretaceous in present-day Madagascar, the more we see that its unique biotic signature goes far into the past and does not simply reflect the island ecosystem of recent times.
Questions and Answers from Readers: Why Were Birds the Only Dinosaurs to Survive Mass Extinction?
Asked by: Edward Seymour, Hove
The asteroid that caused the extinction at the end of the Cretaceous struck the Earth with 60,000 times the energy of all the nuclear arsenal in the world. The atmosphere would have glowed red for several hours, and any large dinosaurs that could not burrow or hide underwater were immediately burned out.
When the smaller species emerged from their hiding places, they found a charred landscape and air so thick with clouds of soot and sulfur dioxide that the sunlight was almost completely blocked for the following year. It was too dark for photosynthesis, so the herbivores died, then the carnivores.
Birds are descended from Maniraptoran dinosaurs but they have had two important adaptations that have helped them survive. First, they had beaks instead of teeth, which allowed them to break seeds and nuts buried in topsoil.
Second, their relatively large skull capacity suggests that they were smarter than other reptiles. They may have lived in more complex social groups that could cooperate and adapt to find new sources of food in a radically different post-apocalyptic landscape. This allowed them to eventually outperform any other species of small dinosaurs that might have survived the initial impact.
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