80 million-year-old world’s smallest and well-intact dinosaur egg fossil discovered

Researchers in China have unveiled a groundbreaking find: the smallest dinosaur egg fossil ever discovered, which has been linked to a new dinosaur species.

In 2021, at a construction site in Ganzhou, researchers unearthed a cluster of six dinosaur eggs dating back to the Late Cretaceous period. The eggs were discovered in a well-preserved nest, providing valuable contextual information about the nesting behavior of this ancient species.

While the name Ganzhou might not be familiar to everyone, the Ganzhou Basin in Jiangxi Province, South China, is renowned among paleontologists as one of the “richest egg fossil sites in the world.”

This site has now yielded the remains of an entirely new dinosaur species, estimated to be over 80 million years old. Notably, the abundance of fossil discoveries in the Ganzhou Basin underscores its importance for understanding dinosaur evolution in Asia.

As paleontologists stated in a new study, “This discovery increases the diversity of dinosaur eggs in the Late Cretaceous and is significant for our understanding of the evolution of theropods in the Late Cretaceous.” Specifically, it challenges previous assumptions about the size and morphology of theropod eggs.

Studying an 80 million-year-old dinosaur egg

According to Global Times, A joint research team from the China University of Geosciences (Wuhan) and the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, led by Lou Fasheng, conducted a meticulous analysis of the six eggs.

Utilizing advanced technology like electron microscopy scanning and electron backscatter diffraction, they examined the surface and crystallographic structure of the eggs. Micro-CT scanning allowed them to reconstruct the fossils’ burial state and gain insights into the dinosaur’s reproductive system.

They also investigated the micro and macro structures of the eggs, including the thickness of their shells. These non-destructive techniques allowed researchers to study the delicate fossils without causing damage.

After an extensive three-year study, they confirmed that the eggs belonged to a new genus and dinosaur species . Named Minioolithus ganzhouensis , this non-avian theropod was previously unknown, characterized by “a small egg size, irregular egg arrangement, worm-like and nodular ornamentation, and a gradual boundary between two structural layers.”

A small egg, a big discovery

The most intact egg, measuring just 29mm, has set a new world record for the smallest dinosaur egg fossil ever discovered, according to the Chinese Academy of Sciences. This tiny but remarkable find offers paleontologists valuable new information about the diversity of dinosaur eggs and the evolution of theropods during the Late Cretaceous period.

The next phase of research aims to gain “deeper insights into the life and ecology of these ancient creatures,” Global Times concluded .

The study was just published in Historical Biology .