Archaeopteryx was first described as the ‘missing link’ between reptiles and birds in 1861 — and is now regarded as the link between dinosaurs and birds. Only 12 specimens have ever been found and all are from the late Jurassic of Bavaria, Germany, dating back approximately 150 million years. Now, Dr. Martin Kundrát from the University of Pavol Jozef Šafárik and co-authors have identified a new species of Archaeopteryx — named A. albersdoerferi — that is closer to modern birds in evolutionary terms.
Using synchrotron microtomography, Dr. Kundrát and colleagues examined one of 12 Archaeopteryx specimens, known as ‘specimen number eight.’
“This Archaeopteryx individual is physically much closer to a modern bird than it is to a reptile,” the paleontologists said.
“Therefore, it is evolutionary distinctive and different enough to be described as a new species — Archaeopteryx albersdoerferi.”
Some of the differing skeletal characteristics of Archaeopteryx albersdoerferi include the fusion of cranial bones, different pectoral girdle (chest) and wing elements, and a reinforced configuration of carpals and metacarpals (hand) bones.
These characteristics are seen more in modern flying birds and are not found in the older Archaeopteryx lithographica species, which more resembles reptiles and dinosaurs.
Specimen number eight is the youngest of all the 12 known specimens by approximately half a million years. This age difference in comparison to the other specimens is a key factor in describing it as a new species.
“By digitally dissecting the fossil we found that this specimen differed from all of the others,” said co-author Dr. John Nudds, from the School of Earth and Environmental Sciences at the University of Manchester.
“It possessed skeletal adaptations which would have resulted in much more efficient flight.”
“In a nutshell we have discovered what Archaeopteryx lithographica evolved into — i.e. a more advanced bird, better adapted to flying — and we have described this as a new species of Archaeopteryx.”
“This is the first time that numerous bones and teeth of Archaeopteryx were viewed from all aspects including exposure of their inner structure,” Dr. Kundrát said.
“The use of synchrotron microtomography was the only way to study the specimen as it is heavily compressed with many fragmented bones partly or completely hidden in limestone.”
“Whenever a missing link is discovered, this merely creates two further missing links — what came before, and what came after,” Dr. Nudds said.
“What came before was discovered in 1996 with the feathered dinosaurs in China. Our new species is what came after. It confirms Archaeopteryx as the first bird, and not just one of a number of feathered theropod dinosaurs, which some authors have suggested recently. You could say that it puts Archaeopteryx back on its perch as the first bird.”
The discovery is reported in the Historical Biology, an international journal of paleobiology.
Martin Kundrát et al. 2019. The first specimen of Archaeopteryx from the Upper Jurassic Mörnsheim Formation of Germany. Historical Biology 31 (1); doi: 10.1080/08912963.2018.1518443