The first case of a crocodile carrying itself was identified in a zoo in Costa Rica.

She gave birth to a fetus that was 99.9% genetically identical to her.

The phenomenon of “virgin birth” has been found in species of birds, fish and other reptiles, but never before in crocodiles.

Scientists say this trait may have been inherited from an evolutionary ancestor, so dinosaurs may also have been capable of self-reproduction.

The egg was laid by an 18-year-old female American alligator in Parque Reptilania in January 2018. The embryo inside was fully formed but was stillborn and therefore did not hatch.

The crocodile that laid the egg was obtained when it was two years old and stayed away from other crocodiles throughout its life. For this reason, the park’s scientific team contacted an American team from Virginia Polytechnic, which specializes in virgin births, scientifically known as parthenogenesis.

They analyzed the fetus and found that it was more than 99.9% genetically identical to its mother – confirming that it had no father.

Writing in the Journal of the Royal Society Biology LettersThe researchers say that virgin births may be more common in crocodiles, and have gone unnoticed until now because people haven’t looked for cases of them.

“It is not uncommon for captive reptiles to lay clutches of eggs, given the period of isolation from mates, as these are usually considered nonviable and discarded. These results therefore suggest that eggs should be assessed for potential viability when males are absent,” he says. Scientists in their research paper.

“Moreover, because[virgin births]can occur in the presence of potential mates, examples of this may be missed when reproduction occurs in females cohabiting with males.”

It’s unclear why parthenogenesis occurs in different species, but the events are repeated in the scientific literature often, perhaps because researchers are looking for them now. One theory is that it occurs in species capable of parthenogenesis when numbers have dwindled, and they are on the verge of extinction.

“Particularly the dinosaurs,” the scientists wrote, “this new evidence provides exciting insights into the potential reproductive capabilities of extinct relatives of crocodiles.”