Renowned as the first fossil feather ever known, the 150-million-year-old isolated fossil feather found in the Jurassic limestone deposits of Solnhofen, Germany, in 1861 is an upper major primary covert of Archaeopteryx, according to new research.
Left: optical photograph of the 150-million-year-old isolated fossil feather of Archaeopteryx. Scale bar – 5 mm. Upper right: the Berlin skeletal specimen of Archaeopteryx. Scale bar – 5 cm. Bottom right: a wing of Archaeopteryx; black represents upper major primary coverts (UMPCs), dark gray represents primaries, and light gray represents secondaries and upper major secondary coverts. Image credit: Carney et al, doi: 10.1038/s41598-020-65336-y / 10.1038/ncomms1642.
Dr. Ryan Carney from the University of South Florida and his colleagues analyzed nine attributes of the 150-million-year-old feather, particularly the long quill, along with data from modern birds.
The researchers also examined the 13 known skeletal fossils of Archaeopteryx, three of which contain well-preserved primary coverts.
They found that the top surface of an Archaeopteryx wing has primary coverts that are identical to the isolated feather in size and shape.
The isolated feather was also from the same fossil site as four skeletons of Archaeopteryx, confirming their findings.
“There’s been debate for the past 159 years as to whether or not this feather belongs to the same species as the Archaeopteryx skeletons, as well as where on the body it came from and its original color,” Dr. Carney said.
“Through scientific detective work that combined new techniques with old fossils and literature, we were able to finally solve these centuries-old mysteries.”
Using a specialized type of electron microscope, the scientists determined that the feather came from the left wing of Archaeopteryx.
They also detected melanosomes, which are microscopic pigment structures.
After refining their color reconstruction, they found that the feather was entirely matte black.
“We provide additional insights, such as an updated color reconstruction of the entire feather as matte black, with 90% probability,” the authors said.
“Given the isolated nature of the fossil feather, we can never know the anatomical and taxonomic provenance with 100% certainty.”
“However, based on all available anatomical and taxonomic evidence, independently confirmed by close morphological connections to multiple skeletal specimens, the most empirical and parsimonious conclusion is that the isolated feather represents a primary covert of Archaeopteryx.”
The team’s paper was published online in the September 30, 2020 issue of the journal Scientific Reports.
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R.M. Carney et al. 2020. Evidence corroborates identity of isolated fossil feather as a wing covert of Archaeopteryx. Sci Rep 10, 15593; doi: 10.1038/s41598-020-65336-y
