Qualla: Jehol Biota

Jehol Biota: Introduction

Sat, 14 Mar 2026 00:00:00 GMT

Photo credit Llez (H. Zell)., CC BY-SA 3.0. Imagine a world of temperate forests and freshwater lakes, periodically buried under volcanic ash, where feathered dinosaurs hunted in the canopy and some of the earliest flowering plants grew at the water's edge. This was northeastern China between 133 and 120 million years ago, during the Early Cretaceous. The Jehol Biota -- named for the historical Rehe Province where its fossils are found -- is not a single spectacular specimen but an entire ecosystem, preserved in such extraordinary detail that scientists can reconstruct not just what lived here, but how it lived, what it ate, and what color it was.

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Image: Llez (H. Zell). | CC BY-SA 3.0

Jehol Biota: A World Sealed in Ash

Sat, 14 Mar 2026 00:00:00 GMT

Photo credit ScottRobertAnselmo, CC BY-SA 3.0. The Jehol Biota is preserved primarily in the Yixian and Jiufotang Formations, layers of lacustrine sediment interbedded with volcanic ash. The preservation is so exceptional that these formations qualify as Lagerstatte -- sites of extraordinary fossil quality. Animals and plants...

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Image: ScottRobertAnselmo | CC BY-SA 3.0

Jehol Biota: Refuge and Laboratory

Sat, 14 Mar 2026 00:00:00 GMT

Photo credit ScottRobertAnselmo, CC BY-SA 3.0. The Jehol Biota is scientifically remarkable for containing both ancient relict species and the earliest members of lineages that would later dominate the planet. The compsognathid Sinosauropteryx and the pterosaur Dendrorhynchoides were holdovers from the Late Jurassic, survivor...

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Image: ScottRobertAnselmo | CC BY-SA 3.0

Jehol Biota: The Diversity That Changed Science

Sat, 14 Mar 2026 00:00:00 GMT

Photo credit ScottRobertAnselmo, CC BY-SA 3.0. The sheer variety of Jehol organisms rewrote multiple chapters of paleontology. The biota includes the earliest known angiosperms -- flowering plants, including the aquatic Archaefructus. Insects experienced their largest Mesozoic diversification. Mammals grew to sizes never befo...

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Image: ScottRobertAnselmo | CC BY-SA 3.0

Jehol Biota: A Climate Colder Than Expected

Sat, 14 Mar 2026 00:00:00 GMT

Photo credit ScottRobertAnselmo, CC BY-SA 3.0. One of the Jehol Biota's most surprising revelations concerns climate. Oxygen isotope analysis has shown that average yearly temperatures during the Early Cretaceous in this region were around 10 degrees Celsius -- far colder than the uniformly warm world that scientists had long...

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Image: ScottRobertAnselmo | CC BY-SA 3.0