A crocodile has made herself pregnant in what is believed by scientists to be a world first. The crocodile at the Costa Rica zoo created a foetus that was 99.9 per cent genetically identical to itself, often known as a "virgin birth." This process typically does not occur with crocodiles but with other species such as birds, lizards, snakes, fish and sharks. Sign up to our free Indy100 weekly newsletter Scientists believe this kind of solo reproduction could be traced back to the dinosaurs, as they suggest the species may have also been capable of this rare method. The latest study was published on Wednesday (June 7) in the Royal Society journal, Biology Letters. Back in January 2018, an egg was laid by an 18-year-old female American crocodile in Parque Reptilania, the BBC reported. The fully formed foetus did not hatch however and was stillborn. Researchers from Virginia Polytechnic Institute and State University, say this is the "first documentation" of this kind of reproduction in this species. Dr Warren Booth who has studied virgin births (parthenogenesis) for 11 years theorised that this reproduction method has not been seen in crocodiles because weren't looking out for this happening. ''There was a big increase in reports of parthenogenesis when people started keeping pet snakes. But your average reptile keeper doesn't keep a crocodile," he noted to the BBC. "This new evidence offers tantalizing insights into the possible reproductive capabilities of extinct archosaurian relatives of crocodilians, notably the Pterosauria and Dinosauria," experts said in the study. Have your say in our news democracy. Click the upvote icon at the top of the page to help raise this article through the indy100 rankings.