Researchers find crocodile living alone in a Costa Rica zoo had a virgin birth

In an astounding case, researchers have found that an egg laid in 2018 by a female crocodile living alone in a Costa Rica zoo was not only fertile, it also contained genetics only from its mother.

In essence, the crocodile had just had a virgin birth.

In a paper published Wednesday from the Biology Letters journal, researchers said the unusual reproduction from the crocodile was the first evidence ever found in that species. The 18-year-old crocodile, which arrived at the Parque Reptilandia zoo in 2002, had been isolated from other crocodiles its entire life. The crocodile laid a cluster of 14 eggs, which is not unusual, but seven of those eggs appeared to be fertile. The fertile eggs were artificially incubated for another three months, but failed to hatch and were opened.

Of the seven fertile eggs, one of the eggs had a fully formed, but stillborn, fetus. It was considered to be a parthenogen, or the result of a virgin birth.

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The fully formed crocodile was found to have identical genotypes to its mother, and a lack of paternal genes.

This type of reproduction is called facultative parthenogenesis and has been documented before in animals including birds, non-avian reptiles, specifically lizards and snakes, and certain types of fish, including sharks and stingrays.

Thanks to previous evidence of facultative parthenogenesis in those previous animals and now in crocodiles, researchers said this find could offer "tantalizing insights into the possible reproductive capabilities" of both dinosaurs and pterosaurs, or ancient flying reptiles.

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This article originally appeared on USA TODAY: Crocodile living alone had virgin birth, researchers find