Researchers are thrilled to have discovered the first known venomous frogs in the world. One of them is not so thrilled, however, with how they found out one of the frogs was venomous. When Carlos Jared of the Butantan Institute in São Paulo, Brazil, picked up a Brazilian hylid frog (Corythomantis greeningi, pictured) while doing fieldwork in a jungle in the Goytacazes National Forest near the southwest coast of Brazil, the frog swept the spines hidden within its upper lip across his hand. For the next 5 hours he experienced agonizing pain coursing through his arm.

venemous frog, Corythomantis greeningi (1)

The hidden spines of Photo: Utah State University

It was later determined that the venom of this frog was twice as potent as a deadly pit viper. The only good news was that Jared came in contact with the less potent of the two frogs they discovered. The other one, Aparasphenodon brunoi, also in the Goytacazes National Forest, had a whopping 25 times greater potency than a pit viper’s venom.

venemous frog, Corythomantis greeningi (3)

“I will cut you.” Photo: Carlos Jared

While there are dozens of species of poisonous frogs, these two are the first to be identified as venomous, or having the capability to inject venom into the victim.

“Discovering a truly venomous frog is nothing any of us expected,” lead author Edmund Brodie Jr. of Utah State University said in a statement.

venemous frog, Corythomantis greeningi (2)

Skull of a Corythomantis greeningi frog showing spines Photo: Carlos Jared/Butantan Institute

“We were amazed at the level of toxicity in these frogs,” Brodie told IFLScience. According to their calculations, a gram of A. brunoi’s potent skin secretions would probably be sufficient to end the lives of 300,000 mice, or 80 humans.

Read the full published in Current Biology.