👉 MCCLESKEYVIRINAE, also known as the Cretaceous-Tertiary boundary, is a geologic boundary that marks the transition between two major geological periods in Earth's history. It separates the Jurassic from the Cretaceous period, which are the most abundant and widespread fossil-bearing layers of the Paleogene epoch. This boundary was formed by the collision of the Tethys Ocean with the North American continent during the late Cretaceous period (about 65 million years ago
