Trending Now - Small Dinosaur Fossils Challenge Long-held Evolution Beliefs

WHO:

Earth.com - The study was co-led by Peter Makovicky from the University of Minnesota Twin Cities and Sebastián Apesteguía from Universidad Maimónides in Argentina.

Science Daily - Researchers studied tiny dinosaur fossils that were previously misidentified.

WHAT:

Earth.com - The fossil belongs to Alnashetri cerropoliciensis, a member of the alvarezsaurs group.

Earth.com - Alnashetri weighed less than 2 pounds, making it one of the smallest non-avian dinosaurs ever discovered.

Science Daily - The tiny dinosaur fossils were confirmed to be baby ankylosaurs, some less than a year old, including a possible hatchling.

Earth.com - The study describing the skeleton was published in the journal Nature.

WHERE:

Earth.com - The Alnashetri fossil was discovered in northern Patagonia at the La Buitrera fossil site.

Earth.com - The La Buitrera site has been yielding important finds for over two decades.

WHEN:

Earth.com - The Alnashetri skeleton is approximately 90 million years old.

Earth.com - The significant specimen of Alnashetri was discovered in 2014.

WHY:

Earth.com - The discovery of Alnashetri provides new insight into how its lineage evolved, shrank, and spread across the ancient world.

Earth.com - The research aims to clarify the evolutionary transitions in anatomy and body size of alvarezsaurs.

HOW:

Earth.com - The fossil preparation involved years of careful cleaning and assembling to avoid damage.

Science Daily - Researchers studied bone growth patterns to confirm the identity of the tiny dinosaur fossils.

(UPDATED April 22, 2026 04:02 UTC)

A recent study co-led by Peter Makovicky from the University of Minnesota Twin Cities and Sebastián Apesteguía from Universidad Maimónides in Argentina has confirmed the identity of tiny dinosaur fossils previously misidentified, revealing them to belong to Alnashetri cerropoliciensis, one of the smallest non-avian dinosaurs ever discovered, weighing less than 2 pounds. The Alnashetri fossil, found in northern Patagonia at the La Buitrera fossil site, is approximately 90 million years old and was discovered in 2014, providing new insights into the evolutionary transitions of alvarezsaurs. Researchers spent years carefully preparing the fossils and studying bone growth patterns to clarify the anatomy and body size changes in this ancient lineage.