A female crocodile has had what zookeepers call a “virgin birth” after making herself pregnant.

The crocodile is the first recorded reptile to make herself pregnant. After keeping her in captivity from males for 18 years, zookeepers found a fully formed stillborn fetus in an egg. After examination, scientists discovered the egg had a 99.9% genetic code identical to the mother.

Although the croc is the first recorded reptile to have an immaculate conception, virgin births are quite common in the animal kingdom. Turns out girls run the world after all.

‘Virgin births’ also known as ‘parthenogenesis’, are common in some animal species

This crocodile is the first recorded reptile to have a “virgin birth,” but not the first animal to do so. According to National Geographic, a small portion of animal species can have offspring without breeding through a process called parthenogenesis.

Certain species, including birds, bees, snakes, lizards, fish and even sharks can have “virgin births.” Some recorded instances include the pregnancy of a reticulated python named Thelma at the Louisville Zoo. Another, a zebra shark named Leonie at Australia’s Reef HQ Aquarium.

Sky News reports that the Costa Rican crocodile laid eggs in 2018. Seven eggs were viable and incubated; however, none hatched after three months. One fetus formed fully, but was stillborn.

Dr. Warren Booth, a scientist at Virginia Tech and expert in “virgin births” told the BBC the occurrence did not surprise him.

“We see it in sharks, birds, snakes and lizards and it is remarkably common and widespread’,’ he said.

Other studies from Virginia Tech published in the Royal Society Journal “Biology Letters” speculate parthenogenesis could occur in crocodiles without it being noticed before.

“It is not uncommon for captive reptiles to lay clutches of eggs, given the period of isolation from mates, these would normally be considered non-viable and discarded…These findings, therefore, suggest that eggs should be assessed for potential viability when males are absent.”

Scientists believe this could be an inherited trait from dinosaurs

Booth explained that parthenogenesis is a “mechanism across snakes, many lizards, and birds, is the exact same mechanism that we have found here in crocodiles.”


The first ever case of a crocodile “virgin birth” has been recorded by scientists after a female crocodile in Costa Rica produced a fully formed foetus without any male counterpart. The foetus was 99.9% genetically identical to herself and she hadn’t been in contact with any male crocodiles for 16 years. #costarica #pregnant #crocodile #reptile #birth #reproduction #baby #animalsoftiktok #womenoftiktok #crazyfacts #learnontiktok

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Adding, “As such, this is not likely to be a trait that has evolved independently in each lineage but is instead a trait ancestral to these lineages. What this also tells us, is that as crocodiles and birds use the same mechanism, their extinct relatives — dinosaurs and pterosaurs — are also likely to have been capable of parthenogenetic production. The idea that life finds a way — as in Jurassic Park — is not science fiction at all.”

Although the crocodile fetus did not survive, other species have had successful “virgin births.”

“We have numerous records in birds, snakes, and lizards, that record parthenogens being born, and surviving. As such, with this new record, we are just starting to scratch the surface in understanding the long-term ecological and evolutionary significance of this trait,” Booth said.

Crocodiles come from the evolutionary lineage of archosaurs, which also include birds. The Royal Society Journal “Biology Letters” state that:

“With [facultative parthenogenesis] now documented in the two main branches of extant archosaurs, this discovery offers tantalizing insights into the possible reproductive capabilities of the extinct archosaurian relatives of crocodilians and birds, notably members of Pterosauria and Dinosauria.”