Forget the Dinosaur King: Meet D. Rex, a Giant Fungus from 65 Million Years Ago

In the forests of southwestern China, scientists have discovered a new species of giant fungus dating back about 65 million years, touted as the fungal counterpart of the T. rex.

Dianjunus rex

This intriguing organism was spotted by a team from the Kunming Institute of Botany during fieldwork near the towns of Damaidi, Yipinglang, and Nanbang. The examination of whitish protuberances emerging from the soil revealed the fruiting bodies of an unknown species of ascomycete, a phylum that accounts for about 75% of described fungi (more than 65,000 species).

Standing about fifty centimeters tall and weighing around 2.2 kilograms, these structures release the spores that will allow this giant fungus to colonize new environments.

« This extreme bodily form sheds light on the evolution of fungi and underscores our limited understanding of the fungal biodiversity of East Asian forests », notes Indunil Senanayake, lead author of the new study, published in the journal Frontiers In Fungal Biology.

Genetic and morphological analyses have placed the emergence of the new species at around 65 million years ago, roughly one million years after the asteroid impact that ended the reign of the dinosaurs. Its name, Dianjunus rex, refers to this timeline, its impressive size, and the Dian realm established in what is today Yunnan province two millennia ago.

New Ecological Opportunities

Belonging to the order Xylariales, known for producing enzymes capable of breaking down complex plant matter, D. rex is thought to have developed primarily on dead wood.

« Shortly after the Cretaceous extinction, forests underwent dramatic changes », explains Senanayake. « These environmental perturbations have probably created new ecological opportunities for these organisms. »

While a number of questions remain about how the largest ascomycete known to science could reach such a size and persist for tens of millions of years, it once again highlights the remarkable adaptability of fungi.