1. THE ARRIVAL

A research team working in the forests of Yunnan Province in southwest China has found a new species of fungus, and the fungus is not small, not new to the forest, and not going to pretend otherwise. It grows a fruiting body up to 50 centimeters tall — about the height of a traffic cone, as ScienceAlert noted, with the understatement of the profession — and it can weigh 2.2 kilograms, which is roughly one house cat, seated, unimpressed.

The team named it Dianjunus rex, after the ancient Dian kingdom of the region and for its regal size. The nickname arrived on its own. Gizmodo ran with it, and the internet received it the way the internet receives anything with teeth: Dianjunus rex is “D-rex,” a mushroom that is, functionally, a dinosaur.

2. THE MEASUREMENTS

It is the largest known fruiting body of any member of the phylum Ascomycota, the club fungi, which is a phylum that has spent its entire visible history being overlooked and has now, at the age of 65 million years, been caught being magnificent. It feeds on dead wood. It grows in the shape of a thick pale club. It does not appear to be in a hurry, having had six and a half decades of millennia to prepare.

3. THE LINEAGE

Here is the part that rearranged the filing cabinets. Genetic testing showed the creature belongs to no known family of fungi at all, so the authors created one: Dianjunaceae, a family with exactly one member, which is the taxonomic equivalent of giving a man his own zip code. Its lineage within the order Xylariales dates to roughly the end of the Cretaceous, the extinction that removed the dinosaurs having apparently cleared the shelves for whatever this thing wanted to become. The asteroid fell. The forest, eventually, needed someone to manage the dead wood. A traffic cone stepped forward.

4. THE VIBES

A creature this large, in a province this famous for mushrooms, eluded science until this year, which says less about the mycologists than about the plant. Dianjunus rex does not advertise. It stands in bamboo and rhododendron shade, the size of a throne cushion, doing fungi things, until a human with a measuring tape kneels beside it and both parties agree the moment has come.

The scientific name carries a crown and the nickname carries an asteroid, and the organism itself has commented on neither, because it is a fungus. The type specimen now rests in a herbarium, where, by all accounts, nothing further is happening to it.