During an underwater exploration off the coast of California, oceanographers discovered a mammoth tusk dating back more than 100,000 years. Its preservation, away from light and at low temperatures, will allow the DNA of the specimen to be exploited.
When piloting an unmanned underwater vehicle (more often called ROV, for Remotely Operated underwater Vehicle), oceanographers expect to observe marine species unknown to science, unprecedented behaviors between organisms or even astonishing landscapes that life and currents have shaped. It is, however, a, who works at the Monterey Bay Aquarium Research Institute. In 2019, they were exploring at the level of a at about 3,000 meters deep, 80 kilometers off the coast of California. It was with surprise that they then saw the shape of a tusk tusk take shape. on their screens. They were unable to bring it back to the surface in its entirety during this expedition because a piece broke during collection, which only allowed the team to bring up a fragment of this discovery. In 2021, a new expedition was carried out on this same site in order to bring back the rest of the defense.
This mammoth tusk is not the first to be discovered in the ocean. However, the previous remains of mammoths found in the marine environment (in the North Sea) do not lie so deep, their location does not indeed exceed a few tens of meters below the surface.
Previous mammoth remains found in marine environment don’t lie so deep
Most of the mammoth remains unearthed also come from the permafrost near the Arctic Circle or on dry land, at hunting sites occupied by humans. The presence of the mammoth tusk at a depth of 3,000 meters is therefore surprising, especially since its state of conservation is very good. It will make it possible to obtain images using X-ray tomography and to perform DNA analyzes.
The witness of a hybridization between two species of mammoths?
The tusk is almost a meter long and once belonged to a Columbus mammoth, Mammuthus columbi. This species is known to have inhabited North America in particular (specimens have been found in Arizona, Texas and Florida), theand Costa Rica. Estimates indicate that this species could be over four meters tall and long and weigh between eight and ten tons. Based on the thickness of the iron and manganese crust that formed on the tusk, researchers estimate its age at over 100,000 years. Analyzes are underway to determine a precise age. The are not completed but will provide a better understanding of the evolution of mammoths.
The first mammoths indeed arrived from Eurasia to North America 1.5 million years ago via the Bering Strait and then hybridized with thewhen it joined the Americas several hundred thousand years later. This hybridization would have allowed the emergence of the species M. columbi that hypotheses place at 420,000 years ago. If the tusk of the specimen that was brought up from the depths is therefore as old as researchers assume, it should help date with more certainty the period of this hybridization.