Virgin birth: Female crocodile gives birth in Costa Rica – despite living ALONE for 16 years 

Nature has once again proved that life finds a way, as a female crocodile has given birth to fertilized eggs – despite living alone for the past 16 years.

This is the first time scientists have shown that a crocodile can produce offspring without mating, and they now say dinosaurs could do the same.

Zookeepers discovered that an 18-year-old female American crocodile, a 20-foot apex predator, was guarding a clutch of 14 eggs in her enclosure despite not seeing a male in more than a decade.

It is not entirely uncommon for lone crocodiles to lay unfertilized eggs that are usually discarded; however, researchers were surprised to find that seven of the eggs had actually been fertilized.

Although the eggs failed to hatch after three months of incubation, one was found to contain a fully formed female fetus nearly genetically identical to its mother.

According to Warren Booth, an associate professor at Virginia Tech who led the study, this discovery “could provide tantalizing insights into the possible reproductive capabilities of extinct archosauric relatives of crocodilians,” including the dinosaurs.

Crocodiles branched off from other dinosaurs about 240 million years ago, but these ancient lizards also share a common ancestor with birds that date back at least 267 million years.

With evidence that crocodiles and birds can both produce young without mating, Booth says this ability is “a trait likely possessed by a distant common ancestor of these genera,” meaning dinosaurs, too, may have exhibited “virgin births.” .

However, “virgin birth” is not the product of divine intervention or sneaky visits by male crocodiles at the zoo, but a natural process called facultative parthenogenesis.

Facultative parthenogenesis is the rare ability to produce offspring without the need for sexual reproduction.

While this could be mistaken for a phenomenon called “long-term storage of female sperm,” in which an animal can produce offspring long after mating, researchers used genetic analysis to prove there was no male involvement whatsoever.

The female embryo was 99.9 percent genetically identical to its mother, showing it had no father.

However, this does not mean that it was a clone.

Although the eggs failed to hatch after three months of incubation, one was found to contain a fully formed female fetus nearly genetically identical to its mother (stock image)

This is the first time scientists have shown that a crocodile can produce offspring without mating, and they now say dinosaurs could do the same

The scientists believe the female crocodile fertilized her own eggs, meaning the offspring contained two copies of its mother’s DNA.

What makes this discovery “particularly interesting,” says Booth, is that crocodile reproduction is very different from any other animal previously known to be capable of facultative parthenogenesis.

Crocodiles lack all sex chromosomes – the X and Y components of our DNA – meaning that the sex of crocodile offspring is determined not by their parents, but by the weather.

In a process known as temperature-dependent sex determination, whether a crocodile becomes male or female depends on the temperature at which the egg is hatched.

Above 99ºF (33º) or below 86ºF (30ºC), 100 percent of crocodile eggs become female, while around 89º (31.5ºC) the offspring are mostly male.

This research has been published in Biology Letters from the Royal Society.