According to conclusions of American scientists published in the "Nature Geoscience", an asteroid which caused mass extinction of alive beings on the Earth 66 million years ago, had caused the greatest loss to its northern hemisphere.
The hypothesis about impact of an asteroid with Earth at the boundary of the Cretaceous and Paleogene suggest that impact of the asteroid with Earth resulted in extinction of dinosaurs and the largest part of rest fauna and flora having existed on the planet. Particularly, about 90 % of species of nannoplankton had died out.
Scientists decided to inspect, whether the extinction of nannoplankton on Earth was uniform. They analyzed literary data about reduction of diversity of nannoplankton in the northern and southern hemispheres, and also about speeds of its recovery, and had come to the conclusion that 98 % of species of nannoplankton disappeared in the North, and in the South - only 73 %. Moreover in the southern hemisphere recovery of biodiversity had taken some millenaries, and in the northern one was postponed on 310 thousand years.
According to the explorers, almost complete extinction of nannoplankton in the northern hemisphere was related in that the asteroid had fallen to the ground in the northern latitudes. Its fall had led to atmospheric emission of large quantity of heavy metals which were toxic for living organisms.
My commenting: The data, published in "Nature Geoscience" are of the great interest, and, in no smaller degree, confirm the most ancient Indian and slavonic legends about occuring in "the epoch of domination of different types of snakes (dragons)" war between white gods landed on the Earth - adityas led by Indra or Svarog and former inhabitants of the Earth - dragon-people led by Vritra or Chernobog, the main focus of which, apparently, was on the northern continent Hyperborea. Though it is nesessary to mean that data in this respect are rather poor.