Patagonian Rosetta Stone Dinosaur Rewrites Alvarezsaurs' Size Story
A near-complete, adult Alnashetri cerropoliciensis skeleton from Patagonia, dating to about 90 million years ago and weighing under 2 pounds, provides a crucial reference for the alvarezsaurs. The find challenges the idea of a simple miniaturization trend, suggesting repeated evolution within a narrow size range and pointing to a Pangaea-era origin with regional diversification.