Washington: A new discovery of amber fossil has linked the earliest grasses, dinosaurs and fungus used to produce LSD.

A perfectly preserved amber fossil from Myanmar has been found that provides evidence of the earliest grass specimen ever discovered - about 100 million years old - and even then it was topped by a fungus similar to ergot, which for eons has been intertwined with animals and humans.

Ergot has played roles as a medicine, a toxin, and a hallucinogen; been implicated in everything from disease epidemics to the Salem witch trials; and more recently provided the hallucinogenic drug LSD.

Apparently both ergot and the grasses that now form most of the diet for the human race evolved together.

And if they already seemed a little scary, imagine a huge sauropod dinosaur that just ate a large portion of this psychotropic fungus, which in other animal species can cause anything from hallucinations to delirium, gangrene, convulsions or the staggers. The fungus, the grasses it lived on and dinosaurs that ate grass co-existed for millions of years.

The fungus in this grass specimen, which is now extinct, was named Palaeoclaviceps parasiticus. It's very similar to the fungus Claviceps, commonly known as ergot.

Researchers also noted in their report that few fungi have had a greater historical impact on society than ergot.

Some grasses have natural defense mechanisms, and ergot may be one of them, helping to repel herbivores. It's bitter and not a preferred food to livestock and it's still a problem in cereal and grass seed production, as well as pastures and grazing land.

More than 1,000 compounds have been extracted or derived from it, some of them valuable drugs. They also included, in the mid-1900s, the powerful psychedelic compound lysergic acid diethylamide, or LSD, that is still being studied and has been widely used as an illegal recreational drug.