A documented case of a crocodile virgin birth

A case of a virgin crocodile producing fertile eggs has been reported by a team of entomologists and reptile experts from Virginia Polytechnic Institute and State University, the Chiricahua Desert Museum, the Illinois Natural History Survey, Reptilandia Reptile Lagoon, and Parque Reptilandia. The team's amazement at finding a clutch of eggs deposited by an American crocodile who had been kept alone in an enclosure at the Parque Reptilandia park in Costa Rica for 16 years is detailed in their research that was just published in the journal Biology Letters.

Prior studies have discovered cases of "virgin birth"—a sort of asexual reproduction in a species that typically reproduces sexually—in snakes, lizards, sharks, and birds, but never in the order Crocodilia, which includes gharials, caimans, alligators, and crocodiles. As a result, the Parque Reptilandia keepers were taken aback when they noticed a clutch of eggs in a cage housing a lone American crocodile.

Although crocodiles are less well-known in North America than alligators, they may be found in some areas of Florida. They are also found in South and Central America. Like most other reptiles, they typically pair for reproduction and deposit eggs that eventually hatch. But it now seems that, if necessary, they are capable of asexual reproduction.

The 14-egg clutch was found back in 2016. When handlers became aware of their coming, they alerted regional experts. The eggs were gathered and brought to a lab for analysis, where scientists discovered that 50% of them were viable. The fertile eggs were put in an incubator in the hopes that they would hatch into young animals.

Unfortunately, none of the eggs gave birth, so the researchers decided to pry them up after three months to examine what was happening. Even though all of the eggs were nearing hatching, only one of them genuinely resembled a fetus. The most evolved specimen was almost genetically similar to its mother, according to a DNA analysis.

The study team observes that since eggs placed in such a way are uncommon, it was not unexpected that none of the eggs could develop. Virgin births in birds and Crocodilia have already been confirmed, which begs the issue of whether pterosaurs and/or dinosaurs were also capable of doing so.