An ancient amber fossil contains the earliest grass specimen ever discovered, and it was covered in a fungus that may have given dinosaurs that ate it a psychedelic experience.

The 100 million-year-old fungus was similar to ergot, which is used in the drug LSD, Oregon State University reported. The findings suggest the ancient grass and this hallucinogenic fungus evolved together.

"This is an important discovery that helps us understand the timeline of grass development, which now forms the basis of the human food supply in such crops as corn, rice or wheat. But it also shows that this parasitic fungus may have been around almost as long as the grasses themselves, as both a toxin and natural hallucinogen," said George Poinar, Jr., an internationally recognized expert on the life forms found in amber and a faculty member in the OSU College of Science. "There's no doubt in my mind that it would have been eaten by sauropod dinosaurs, although we can't know what exact effect it had on them."

The fungus in the now-extinct grass specimen was called Palaeoclaviceps parasiticus, which is extremely similar to the modern fungus ergot (Claviceps). The fossil was found in amber mines in Myanmar, and dates back to the early-to-mid Cretaceous when dinosaurs still ruled the land.

The researchers noted that "few fungi have had a greater historical impact on society than ergot." The fungus may act as a natural defense system for grasses, helping them repel predatory herbivores. Through history, the bitter fungus has been known to cause "delirium, irrational behavior, convulsions, severe pain, gangrenous limbs and death" in both animals and humans. It has also been used in medicine for purposes such as inducing abortions and speeding up labor in pregnant women and has speculated to have played a role in the infamous Salem witch trials. Compounds extracted from the fungus have been used to create a variety of drugs, including LSD in the mid-1990s. 

"Ergot is strange. And a very, very old fossil now makes clear that it's been around about as long as grass itself," the researchers concluded.

The findings were published in a recent edition of the journal Palaeodiversity.