An ancient bird’s big beak breaks new ground

Every day, scientists uncover startling new information that reshapes our understanding of the ancient world.

The latest groundbreaking discovery concerns a bird from the late Cretaceous period with a very big beak — so big it charts a new course in evolutionary history.

In a study published Wednesday in Nature, researchers describe a previously unknown species, Falcatakely forsterae, an ancient bird with an unusually large beak resembling that of a modern-day toucan.

Big Bird — The researchers first discovered the fossil of this unknown bird species a decade ago in Madagascar.

But the fossil specimen was fragile and contained many small bones, so it wasn't fully analyzed until 2017. But once the researchers had parsed through the tiny fragments, they realized they had unearthed something truly special.

"As soon as we started to carefully remove the rock from around those delicate bones, it very quickly was apparent that it's like, 'Oh, okay, we've got something really neat here,'" Patrick O’Connor, lead author on the study and professor of Anatomical Sciences at Ohio University, tells Inverse.

After removing the rock, the scientists used micro-computed tomography scanners to gather data to simulate the creature's skull in 3D. They then used 3D-printing to build a replica of the bird skull.

"There's a lot of digital modeling that goes into just understanding, you know, what the anatomy is in this new animal," O’Connor says.

Researchers named the species Falcatakely (roughly meaning 'little flying sickle') for its uniquely shaped face. They classified Falcatakely as an enantiornithine bird, a "group of birds that were alive during the time of dinosaurs," O'Connor says. These birds often had teeth and claws on their wings. All known species are now extinct.

Yet, Falcatakely is unlike most other ancient birds which also lived 65-250 million years ago. Although birds from this era — known as the Cretaceous Period — had diverse body shapes, when it came to their faces, they tend to look pretty much the same.

Face Time — But with its long, deep beak, Falcatakely broke the mold.

"We see Falcatakely has a massively divergent shape of the face compared to anything else that it is related to," O'Connor says.

This bird's big beak more closely resembles those of modern birds.

This is a curious finding. Modern birds are much more diverse than ancient ones when it comes to their faces. Anatomy can help explain the difference between most ancient birds — apart from the Falcatakely — and modern ones. It all comes down to a bone in their skulls: the premaxilla bone. Located on the top of a bird's beak, ancient birds seem to not have used this bone for feeding, whereas modern-day birds do.

"All of that diversity in modern bird face shape is really driven by a bone called the premaxilla bone," O'Connor says. "And that's the bone that does all of this crazy differentiation through development to give you that vast array of face shapes that we see around us today."

Spurred on by the Falcatakely's unique face shape, the researchers wanted to understand "what is driving face shape, not only in modern birds and in enantiornithine birds," according to O'Connor.

They compared the bone structure of the newly discovered bird to other creatures — including non-avian ones, like dinosaurs.

"We take a broader perspective to say, okay, we can look at a full range of animals that are relatively closely related to one another. Some of them are modern birds, some of them are Mesozoic birds and then those non-avian dinosaurs that are the closest relatives to the avian radiation," O'Connor says.

They discovered the Falcatakely may have had a similar look to modern birds as a result of convergent evolution, which occurs when unrelated animals evolve in similar ways and share the same traits. But unlike modern birds, the Falcatakely gets its broad beak by expanding the maxillary bone, another bone in the skull.

"The point of the convergence is that it does have that general overall shape, but it doesn't do it by modifying the same bones of the face that we see in modern birds," O'Connor says. Rather, this bird's beak is closer to the structure of one of the most ferocious dinosaurs — velociraptors.

"It's using what we've described as a kind of a primitive arrangement of bone structure that's more similar to things like the velociraptor or microraptor."

A new path — The findings carve a new path in the fossil record and upend scientists' beliefs about what ancient birds may have looked like.

"We would have never predicted something like this would have, you know, a great big and large bill, and that it would be based on the maxilla, because we've never seen that in the fossil record before," O'Connor says

But, more importantly, the study reshapes our understanding of ancient birds and how they evolved.

"Birds alive in the Mesozoic were much more diverse than what we've ever known," O'Connor says.

Abstract: Mesozoic birds display considerable diversity in size, flight adaptations and feather organization1–4, but exhibit relatively conserved patterns of beak shape and development5–7. Although Neornithine (that is, crown group) birds also exhibit constraint on facial development8,9, they have comparatively diverse beak morphologies associated with a range of feeding and behavioural ecologies, in contrast to Mesozoic birds. Here we describe a crow-sized stem bird, Falcatakely forsterae gen. et sp. nov., from the Late Cretaceous epoch of Madagascar that possesses a long and deep rostrum, an expression of beak morphology that was previously unknown among Mesozoic birds and is superficially similar to that of a variety of crown-group birds (for example, toucans). The rostrum of Falcatakely is composed of an expansive edentulous maxilla and a small tooth-bearing premaxilla. Morphometric analyses of individual bony elements and three-dimensional rostrum shape reveal the development of a neornithine-like facial anatomy despite the retention of a maxilla–premaxilla organization that is similar to that of nonavialan theropods. The patterning and increased height of the rostrum in Falcatakely reveals a degree of developmental lability and increased morphological disparity that was previously unknown in early branching avialans. Expression of this phenotype (and presumed ecology) in a stem bird underscores that consolidation to the neornithine-like, premaxilla-dominated rostrum was not an evolutionary prerequisite for beak enlargement.