We’ve all seen two-headed animals. Maybe not in person, but the phenomenon (which we’ll discuss later on in this article) is common enough in nature that we humans have developed a deep fascination with it. In the old days, such specimens might become circus or carnival acts. Today? They’re social media darlings.
Some species are far more – or less – likely to produce two-headed offspring. Reptiles are far more likely to produce this phenomenon than mammals. For example, dual-noggined snakes are far more common than the “freak” livestock we occasionally see (for lack of a better term). This past Wednesday, however, Edisto Beach State Park’s sea turtle patrol found a far rarer specimen than both: a teeny, tiny two-headed loggerhead sea turtle!
South Carolina State Parks shares the news on their official Facebook with photos, which you can see below.
“Edisto Beach State Park sea turtle patrol had a very rare find during a routine nest inventory,” the park begins. “Three to five days after a sea turtle nest shows signs of a major emergence, we dig down to determine the success of the nest by counting the hatched eggs, unhatched eggs and on occasions also find live hatchlings. While performing an inventory this past Wednesday, patrollers and volunteers found three alive loggerhead sea turtle hatchlings still in the chamber, but one hatchling in particular stood out because it had two heads!”
A successful outing for these wonderful SC Outsiders, indeed!
Yet it still begs the question for fellow curious Outsiders: What causes two-headed baby animals to be born?
What Causes Two-Headed Babies – Like This Sea Turtle – to be Born?
According to Edisto Beach State Park themselves, “This two-headed hatchling is the result of a genetic mutation.”
Dr. Justin Adams of Monash University, however, has a far more specific answer. From humans to snakes, Adams studies animal anatomy across the board, and has the answer Outsiders seek.
“Two heads can result from the incomplete splitting of an embryo (also called axial bifurcation),” Dr. Adams explains to ABC.net’s Science division. “This process leads to conjoined twins in humans, although only a very small number of conjoined twins have two heads and one body.”
It is also possible, Dr. Adams says, “for two separated embryos to incompletely fuse to form a two-headed animal.”
As for what makes this process more common in reptiles like turtles and snakes, Adams says ‘fact-checking’ by mammal mothers’ bodies tend to “prevent the implantation of embryos that carry errors like this.”
“If there are errors in development, there are miscarriages and spontaneous abortions,” he adds.
If you’re worried about Edisto Beach State Park’s little two-headed turtle, though, don’t be! “After a few photos, this hatchling, along with the two others found, were released into the ocean,” the park’s post continues.