November 25, 2020 | David F. Coppedge

This Dinosaur-Era Bird Was Not Evolving

The only fossil evidence was a larger beak than expected. From that, a scenario of evolution was built.

All the news media published their just-so story simultaneously, complete with artist reconstructions: a new bird, named Falcatakely (no, not Fake-i-tell-ye), emerged into storyland from a single skull found in Madagascar. The three-inch skull, being delicate, was not even extricated from the rock. Instead, American scientists performed a micro-CT scan on it to reconstruct the pieces in a computer model. The model is shown in Phys.org‘s coverage, “Bird with tall, sickle-shaped beak reveals hidden diversity during the age of dinosaurs.” But first, the Darwin worship service:

Birds have played a pivotal role in shaping our understanding of biological evolution. As long ago as the mid-19th Century, Charles Darwin’s keen observations on the diversity of beak shape in Galapagos finches influenced his treatise on evolution through natural selection. This fossil bird discovery adds a new twist on the evolution of skulls and beaks in birds and their close relatives, showing that evolution can work through different developmental pathways to achieve similar head shapes in very distantly related animals.

The find is published in Nature by Patrick O’Conner et al. (25 Nov 2020), “Late Cretaceous bird from Madagascar reveals unique development of beaks.” In a companion piece by Daniel Field in the same issue, some twists are revealed in the story. First, an affirmation of the plot line, “The fossil record traces the origin of the modern bird skull as birds evolved from their dinosaurian ancestors.” Then, Field does the twist: “Now the discovery of a bizarre fossil reveals a surprising diversion during this process of facial transformation.”

Artist conception of Falkatakely. Note: feathers, feet, body, tail, body shape and colors not found with fossil. Credit: Mark Witton.

Only by looking below the fold does the reader learn that this fossil is problematic for the evolution story:

  • No part of the animal below the skull was found, but the artist reconstruction showed a colorful bird with long tail feathers.
  • The skull looks modern, and the beak resembles those of modern toucans.
  • The storytellers have to invoke “convergent evolution” to explain this bird’s toucan-like beak. Live Science repeats this tale.
  • They invoke futureware to explain the whole bird, according to New Scientist.

In living birds, the upper part of the beak is made up of a single bone called the premaxilla, but early birds from the dinosaur era had beaks made up of two bones. Falcatakely had the primitive arrangement but a modern shape, which Brusatte says “shows that, over millions of years, distantly related birds can evolve similar beak shapes using completely different bone arrangements”.

That Falcatakely is unlike any other Mesozoic bird known so far hints that there are other unusual avians out there. “A species like Falcatakley does provide the tantalizing possibility of a greater diversity of form that remains to be discovered,” says Brusatte.

Falcatakely is classified among the Enantiornithines (“opposite-birds”) because of its designation as Cretaceous. To avoid the puffery of jargon, we can just call this bird one of the Opposite-Birds, as opposed to the Normal-Birds. But they are not really opposites, like the enantiomers of amino acids, which are mirror images of two forms. More accurately, enantiornithines could be called “Other-Birds.” And so Falcatakely is one of those Other-Birds. Ah, science.

Daniel Field pictures “Other-Birds” as inventors. Stuff didn’t just happen to them (a la natural selection); the Other-Birds made things happen. They were like scientists experimenting with beak shapes in the lab.

Modern birds originated in the Late Cretaceous, and it has become increasingly apparent that the final 20 million years of the age of the dinosaurs (86 million to 66 million years ago) was a pivotal time in avian evolutionary history. The discovery of Falcatakely shows us that the importance of this window in time for bird evolution extends well beyond the origin of modern birds. Apparently, ‘pre-modern’ bird lineages such as Enantiornithes were still experimenting with bold new forms — and possibly previously unfilled ecological niches — well into the terminal stages of the Cretaceous.

Do evolutionary paleontologists know why birds were experimenting with beak shape? Did their theory predict that this one would be found? Do they know why the Other-Birds went extinct? Do they have a consistent story? No, Field admits. It’s going to take more work. That’s why Darwinian evolution is so popular among storytellers. It gives them job security.

The pre-modern birds were wiped out in the end-Cretaceous mass extinction event, along with all other dinosaurs, apart from modern birds. Considering the impressive diversity and global distribution of Enantiornithes in the Late Cretaceous, determining why they disappeared in that mass extinction, whereas the earliest modern-bird lineages survived, remains one of the greatest mysteries in avian evolutionary history. The answers to such questions, much like the unexpected anatomy of creatures such as Falcatakely, can be revealed only by evidence from the fossil record. So, let’s keep digging.

In short, this unexpected Other-Bird was not predicted, and required auxiliary hypotheses like convergent evolution to force-fit the fossil into a Darwinian explanation.

Creationists believe in digging and observing, too. But the only prediction that can be made when Darwinians keep digging is that no matter what is found—even if a Precambrian rabbit turned up—they will find a way to offer it in sacrifice to Saint Charlie. Of that one can be sure.

 

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Categories: Birds, Fossils

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