46,000-Year-Old Horned Lark Found in Siberian Permafrost
In a new study published in the journal Communications Biology, an international team of researchers radiocarbon-dated an exceptionally well-preserved carcass of an ancient bird found in the Siberian permafrost and identified the species through reconstruction of its mitogenome.
Permafrost deposits containing both animal and plant material represent a unique opportunity to reconstruct paleoenvironments.
In recent years, permafrost sites in the Arctic have revealed a wealth of frozen animal carcasses from the last Ice Age, including mammoths, woolly rhinoceroses, horses, bisons, and wolverines.
These remains are of great interest to paleontology since they enable a better understanding of the impact of climate change on species, populations, and communities.
In 2018, the frozen near-complete carcass of a passerine bird was recovered in permafrost from a site 30 km (18.6 miles) east from the village of Belaya Gora in Yakutia.
Dr. Nicolas Dussex, a scientist at Stockholm University, the Swedish Museum of Natural History and the Centre for Palaeogenetics, and his colleagues dated the specimen to 46,000 years old.
The researchers then used 50 mg of the bird tissue for DNA extraction and genome sequencing.
They reconstructed the bird’s mitogenome and extracted a partial COI gene, which is used for species identification.
They searched for matches with this gene in GenBank avian genetic databases and found a 100% identity match with the horned lark (Eremophila alpestris), a species of lark in the Alaudidae family found across the northern hemisphere.
“Not only can we identify the bird as a horned lark,” Dr. Dussex said.
“The genetic analysis also suggests that the bird belonged to a population that was a joint ancestor of two sub species of horned lark living today, one in Siberia, and one in the steppe in Mongolia.”
“This helps us understand how the diversity of subspecies evolves.”
During the last Ice Age, the steppe spread out over northern Europe and Asia and was home to now extinct species such as the woolly mammoth and the woolly rhinoceros.
According to one theory, this ecosystem was a mosaic of habitats like such as steppe, tundra and coniferous forest.
At the end of the Ice Age, the steppe was divided into the biotopes we know today — tundra in the north, taiga in the middle and steppe in the south.
“Our results support this theory since the diversification of the horned lark into these sub species seems to have happened about at the same time as the mammoth steppe disappeared,” said Professor Love Dalén, also from Stockholm University, the Swedish Museum of Natural History and the Centre for Palaeogenetics.
N. Dussex et al. 2020. Biomolecular analyses reveal the age, sex and species identity of a near-intact Pleistocene bird carcass. Commun Biol 3, 84; doi: 10.1038/s42003-020-0806-7