Video of a large tarantula dragging off a small opossum is a little gruesome, but it also provides new insight into the lives of animals in the Amazon rainforest.

A team of researchers led by University of Michigan biologists found some surprising things about the diets of large spiders and centipedes in the Amazon, according to a news release from the university.

Namely, that those creatures are eating more small vertebrates, like frogs, lizards and snakes, than previously thought.

“A surprising amount of death of small vertebrates in the Amazon is likely due to arthropods such as big spiders and centipedes,” said University of Michigan associate professor Daniel Rabosky in the release.

And the small-vertebrate menu the scientists observed included at least one opossum. The misfortunate mammal was a white-bellied slender opossum, a kind of mouse opossum significantly smaller than the Virginia opossum commonly seen in parts of the United States.

In the video above, doctoral candidate Mike Grundler describes the tarantula as “about the size of a dinner plate” and says that seeing the spider eating a mammal was “very unexpected.” The footage of a spider carrying the opossum off begins at about the 11-second mark.

Researchers came across the scene after hearing “sounds of struggle,” Rabosky said in an email to HuffPost. By that point, it was too late for the opossum.