The Nemegt Basin - One of the best field laboratories for interpreting Late Cretaceous terrestrial ecosystems

One of the richest and most productive Late Cretaceous vertebrate regions, both in terms of numbers of specimens and represented biota, is the part of the Gobi Desert in southern Mongolia. The Nemegt Formation is the gem of the region because of its highly diverse fauna confined within a discrete stratigraphic interval that is exposed in a relatively small area (175 by 50 km). The type locality for this stratigraphic unit is located south of Nemegt Uul (Nemegt Mountain), with half a dozen sites scattered through the northern parts of the Nemegt Basin. Although less well documented, the Nemegt Formation is also exposed discontinuously in neighboring basins to the west and northwest. The history of development of the stratigraphy and paleontology of this region is complex and encompassesmore than 70 years of research activities, tens of fossil localities (Fig. 1), hundreds of unique specimens, and remarkable efforts to challenge illegal fossil poaching in the country.