An international team of scientists has discovered a new species of Earth’s famous first bird, Archeopteryx , which confirms its position in the transition between birds and dinosaurs. The new species, named Archeopteryx albersdoerferi ., Is slightly younger and more bird-like. Where other Archeopteryx find themselves midway between birds and dinosaurs, this one has more in common with the creatures we see soaring through the skies today. This closes the mystery about the true ancestor of birds, and allows us to see the order in which some modern characteristics appeared.
Thus, in the Late Jurassic, about 150 million years ago, southern Germany was a shallow sea, dotted with tropical islands. Like an ancient Galapagos, the diversity of these islands apparently fostered rapid evolution. There they have found twelve specimens that represent the first evidence of an animal that combined characteristics similar to modern birds. One of them is Archeopteryx albersdoerferi.
However, paleontologists have continued to debate whether today’s birds descend from this little corner of the world. Benjamin Kear of Uppsala University believes that the identification of Archeopteryx albersdoerferi solves the puzzle.
Primitive bird
The study, published in the journal Historical Biology , states that A. albersdoerferi had thin bones filled with air, like modern birds. The fuze had more space to attach the flight muscles, the skull bones were fused, and there were fewer teeth than in other Archeopteryx. All of this is consistent with a lifestyle that depends on flight. Meanwhile, the debate remains whether other Archeopteryx could actually fly short distances or if they just glided.
A. albersdoerferi lived approximately 400,000 years later than any of the other Archeopteryx specimens that we have found. It was buried in the Mörnsheim Formation, a deposit clearly younger than the strata in which all other known Archeopteryx appear.
“However, when we examined the evolutionary relationships of various Archeopteryx species, we found that their flight-related characteristics had appeared separately from those of the dinosaurs, implying that flying lifestyles have evolved more than once. ” explains Benjamin Kear, from the University of Uppsala (Sweden).
The new species was identified using the specimen found in Daiting (Germany) in 1990. It was in private hands until 2009, when the paleontologist Raimun Albersdoerfer bought it, making it available for study.
The twelve Archeopteryx fossils are so diverse that some have proposed that each is a different species. However, a more detailed categorization places the other eleven fossils into two species: A. lithographica and A. siemensii.
The experts examined the fossils using synchrotron microtomography, a type of X-ray analysis that produces 3D images and reveals the extracted parts in great detail. Among other things, it showed that A. albersdoerferi acquired a number of adult characteristics when it was still a youngster, something that does not appear to be the case with previous members of the genus.
Recent work not only shows that birds are living dinosaurs, but many other species combining wings and feathers with teeth and claws have also been found living in other parts of the world at a similar time. This has raised questions about whether Archeopteryx really is a transitional species, or whether they evolved along a path similar to the true ancestors of birds, before hitting an evolutionary dead end.
Reference: The first specimen of Archeopteryx from the Upper Jurassic Mörnsheim Formation of Germany. Received 28 Aug 2018, Accepted 29 Aug 2018, Published online: 24 Oct 2018. Historical Biology. DOI: https://doi.org/10.1080/08912963.2018.1518443
Image credit: Zhao Chuang and PNSO
