An intact 80-million-year-old fossil is the ‘Rosetta stone’ that guarantees to decipher the evolution of birds | Science | EUROtoday

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In the evolutionary historical past of birds there are 70 million years of questions. During that point, all of the teams of contemporary birds that exist in the present day originated on Earth, though science nonetheless can’t clarify how the transition from historic birds, extra just like dinosaurs, occurred. Now, the evaluation of a fossil with an unprecedented diploma of preservation—and of a hitherto unknown species of chicken, which inhabited what’s now Brazil 80 million years in the past—might assist illuminate what that course of was like. The discovery is taken into account a rosetta stone for the research of birds, because it might assist decipher the mysteries of their evolution. The outcomes of the analysis had been printed this Wednesday within the journal Nature.

Guillermo Navalón, a paleobiologist from Madrid on the University of Cambridge, is without doubt one of the important authors of the analysis – together with the Argentine researcher Luis M. Chiappe – carried out by a global staff of scientists. He was answerable for digitizing the fossil by way of a non-invasive course of and managed to reconstruct what the fossil was like in life. Hestia of Navarrenamed in honor of William Nava, the Brazilian paleontologist who discovered it in 2016. “This fossil is so unique that it responds to many frustrations that scientists have had in bird research for a long time,” explains Navalón.

This uniqueness that the researcher speaks of is defined as a result of all of the fossils of historic extinct birds, belonging to the group of enantiornites, have appeared flattened, like a pancake or pancake, as a result of their bones had been delicate and hole, which makes their preservation troublesome. over the centuries. He Navaornis No, it is nearly intact. This allowed his cranium and mind to be reconstructed in three dimensions. The mind tissue shouldn’t be preserved, however the cranium is, and in these animals—as with people—the bone carefully surrounds the mind. In this fashion, the inner cavities could be noticed, which allowed scientists to make a mildew and replicate the delicate tissue that was inside them.

And when what a mind regarded like, you may perceive lots about evolution and animal habits. “We use a metaphor, perhaps a little pretentious: the Navaornis is a rosetta stone. Just as that stone allowed us to understand hieroglyphics, this helps us understand how birds evolved. We have two evolutionary points—ancient birds and modern birds—and, suddenly, a fossil appears that is in the middle of that process and tells us what could have happened there,” particulars the Spanish paleobiologist.

What occurred within the center? A gradual evolution. At the purpose the place the Navaornis There was already a mixture of historic and trendy components. “It has very advanced features that we believed were exclusive to contemporary birds,” particulars Navalón. For instance, their mind is now not tubular and stretched like that of historic birds, however is starting to be globular, with a spinal twine that arches downward, like in people. “It is one of the most advanced characteristics that we detected,” says the researcher. The cranium of Navaornis It is very notable for being utterly toothless and having a construction paying homage to present birds, regardless of belonging to an archaic evolutionary department.

In the middle, 'Navaornis hestiae', 80 million years old; on the left, 'Archaeopteryx lithographica', 150 million years ago; on the right, 'Tangara seledon', current bird.
In the center, ‘Navaornis hestiae’, 80 million years previous; on the left, ‘Archaeopteryx lithographica’, 150 million years in the past; on the suitable, ‘Tangara seledon’, present chicken.Julia d’Oliveira

Features of primitive birds, such because the cerebellum, had been additionally recognized. In trendy birds it’s often bulbous and within the Navaornis It is totally flat, as occurs in essentially the most primitive lineages. The cerebellum is an space that’s particularly lively throughout flight in modern birds, which sparked the curiosity of scientists. How did this historic species management its flight? Some solutions are nonetheless not out there. In it Navaornisthe encephalon—the a part of the mind concerned in increased cognitive talents—has an intermediate extent, permitting researchers to take a position about how the animal moved and behaved.

Very complicated animals

The important drawback with learning the brand new fossil is that there’s little info to match it with. “We still do not very well understand today’s birds and how changes in the different areas of their brains are related to changes in cognitive abilities,” says Navalón. And birds are animals with very complicated behaviors. Some of them migrate hundreds of kilometers utilizing visible indicators, the Earth’s magnetic discipline, the place of the solar and stars, and even smells to orient themselves. Others have extremely superior courtship methods, together with dancing, singing, displaying plumage, and constructing nests. Several birds, equivalent to crows and parrots, are able to utilizing instruments to acquire meals and even imitate human sounds and phrases. How they do it, in lots of instances, stays a thriller.

Matteo Fabbri, an evolutionary biologist at Johns Hopkins University (USA), was not concerned within the new research, however believes that “these findings are a paradigm shift in evolutionary models, since this new species of bird from the Cretaceous shows a Mystifying set of morphological traits connects modern birds to those of the early Mesozoic more than 200 million years ago. He Navaornis “It illustrates that the skeletal characteristics of modern birds did not appear all at once, but rather in a mosaic and gradually.” The same goes for the evolution of their brains. In other words, the evolution of the skull and brain towards today’s birds was a complex and non-linear transition, in which modern features appeared step by step, according to this specialist.

3D reconstruction of the skull, brain and inner ear of ‘Navaornis hestiae’.Photo: G. N. | Video: Guillermo Navalon

Jesús Marugán, vertebrate paleobiologist and researcher at the Autonomous University of Madrid, believes that this new discovery is not only an advance in the understanding of avian evolution, but also proposes “a new paradigm. Special mention must be made of the digital dimension of this research. “The fact of being able to extract data from a fossil in a non-invasive way is a huge advance.” The methods utilized within the research permit for a millimetric comparability of the morphology of various birds all through the historical past of life on Earth. All with out even having to deal with the fossils.

Fabbri believes the invention is “a milestone that advances the field of bird evolution, after more than two decades of waiting to find the right fossils.” It shouldn’t be attainable to foretell what different essential discoveries will emerge from the identical website the place the Navaornisthough the scientists consulted are certain that they’re originally of what is going to be a wave of revolutionary findings.

https://elpais.com/ciencia/2024-11-16/un-fosil-intacto-de-80-millones-de-anos-es-la-piedra-de-rosetta-que-promete-descifrar-la-evolucion-de-las-aves.html