The Hispaniolan solenodon is a wondrously strange creature.

About the size of a guinea pig, it has a long, hairless snout, sharp little teeth and, to top it all off, venom-laced saliva. Highly endangered, it lives quietly in the forests of the Dominican Republic and Haiti, and scientists have been hard pressed to understand much about its habits and evolution. But in a paper published Tuesday in the Proceedings of the National Academy of Sciences, a diverse group of researchers outline the intriguing conclusions they reached about how the solenodon got its dangerous spit, after they sequenced its genome and analyzed its venom.

It was not easy finding solenodons to study, said Nicholas Casewell, a venom expert at the Liverpool School of Tropical Medicine in England and a co-author of the new paper. The team managed to track down two of the animals in the wild with venom they could sample. At the National Zoological Park in the Dominican Republic, they took blood for genome sequencing from another solenodon — one of a handful of captive specimens in the world. They compared the genome to those of related animals, like hedgehogs, moles and shrews, and identified substances present in the venom, including a set of enzymes called kallikreins.

Kallikreins mince up other proteins, including some involved in maintaining blood pressure. The researchers injected mice with solenodon venom and saw that indeed, while their pulse and breathing did not change, their blood pressure dropped precipitously as soon as the venom went in. This could render prey foggy-headed and easier for the solenodon to finish off, the researchers suggest.

Another venomous mammal among the solenodon’s relatives, the northern short-tailed shrew, also has kallikreins in its venom.