Trending Science: How birds got their beaks and… lost their teeth
Scientists have found the earliest known beak from the fossils of a seabird that lived around 85 million years ago. This very early bird species called Ichthyornis dispar was about the size of a gull, had the sharp teeth of a dinosaur, likely ate fish and shellfish, and lived near an inland sea that once covered parts of North America. It’s widely known that birds evolved from dinosaurs. The earliest known bird-like creatures, such as Archaeopteryx, which lived 150 million years ago, were very different from modern birds. Even though they had wings, their skulls more closely resembled those of dinosaurs. Toothed birds, together with dinosaurs, were wiped out when an asteroid crashed into Earth 66 million years ago. Evolutionary journey from dinosaur to bird The seabird’s fossils were discovered in 1870, but the heads of those first specimens were incomplete and badly crushed. It wasn’t until now that new skulls were uncovered. Interestingly enough back then, the discovery was hailed by none other than Charles Darwin as convincing support for his theory of evolution. Published in the journal ‘Nature’, the findings provide a key link in the evolution of dinosaurs to today’s birds. They reveal that the ancient toothed creature was unlike modern birds because it had jaws full of sharp, curved teeth and a skull with room for large jaw muscles. Through advanced CT imaging scans, a team of scientists from the universities of Bath and Yale in the UK generated a clear 3D picture of the bird’s head. They used a complete skull unearthed in 2014 and two new cranial specimens which were undiscovered in museum collections for years. Stepping stone to modern beaks The 3D reconstruction showed what the beak looked like when it first appeared. It was a horn-covered pincer tip at the end of the jaw. The remainder of the jaw was filled with teeth. The beak served as a kind of substitute hand while the hands transformed into wings. It helped the bird snatch prey from the water, toss it back into its mouth and chomp on it with powerful jaws. Research shows that this new specimen had similar brain proportions to that of a modern bird. However, other parts of the skull more closely resembled those of predatory dinosaurs. “Right under our noses this whole time was an amazing, transitional bird,” Yale palaeontologist and co-author Dr Bhart-Anjan Bhullar, told the UK’s ‘Independent’. “It has a modern-looking brain along with a remarkably dinosaurian jaw muscle configuration.” Speaking to the British newspaper ‘The Guardian’, Dr Daniel Field, University of Bath palaeontologist and the study’s lead author, said: “This discovery is a great example of the necessity of the fossil record for solving evolutionary puzzles.” This early bird has the scientific world talking about evolution, much like it did with Darwin and his contemporaries as far back as the 19th century.
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