A Minnesota man on the hunt for wild mushrooms was scouring the floor of a forest, about a mile from the Mississippi River, when he made an astounding discovery.
It wasn’t a rare mushroom, either. It was twin deer, conjoined at the body but with separate heads and necks. The white-tailed fawns were female, and looked recently dead — they were clean and dry, as if they had just been groomed by their mother. Beyond the two heads, though, much about the fawns was normal: their fur, their heads, their legs. The baby deer even had an “almost perfect” spot pattern running down their shared back, researchers said.
“It’s amazing and extremely rare,” Gino D’Angelo, a University of Georgia researcher who used to work for the Minnesota Department of Natural Resources, said in a statement.
The mushroom enthusiast gave the Minnesota Department of Natural Resources a call in May 2016 to let the agency know about the find. The twins were soon picked up just outside of rural Freeburg, Minnesota, near where the Mississippi flows south into Iowa along the Wisconsin border. Then the fawns were frozen, guaranteeing they would be well preserved and in good condition for scientific study, researchers said.
After that, scientists ran a battery of tests: a full necropsy, a CT scan and magnetic resonance imaging at the University of Minnesota Veterinary Diagnostic Laboratory, researchers said. And now D’Angelo and other researchers have published a paper describing the rare deformity. It appears in the April edition of the journal American Midland Naturalist.
The fawns had never breathed outside air, tests on their lungs revealed. That confirmed that the twins were stillborn. The necropsy showed that the pair shared a liver, which was malformed, and that they had extra intestinal tracts and spleens, researchers said. As for their hearts, there were two — but with one shared pericardial sac, which is the fibrous tissue that surrounds the heart.
What does it all mean? For one, the conjoined deer never stood a chance, researchers said.
“Their anatomy indicates the fawns would never have been viable,” D’Angelo said. “Yet, they were found groomed and in a natural position, suggesting that the doe tried to care for them after delivery. The maternal instinct is very strong.”
But to hear D’Angelo tell it, the discovery is still a remarkable one, even though the deer were born dead: “We can’t even estimate the rarity of this,” he said.
That’s because — as unlikely as conjoined twins may be in domestic cattle or sheep, or even in humans — conjoined twins are even more unusual in wild animals like deer, researchers said. What’s even more surprising is that a set of conjoined deer actually made it all the way to delivery, even if they were stillborn.
Researchers rooted through scientific literature from 1671 to 2006, hunting for cases of conjoined wildlife. Only 19 confirmed instances turned up, they said. And of those 19 cases, only five were animals in the deer family — two of them white-tailed, like the ones found in Minnesota. But those two were undelivered fetuses, researcher said.
“Of the tens of millions of fawns born annually in the U.S., there are probably abnormalities happening in the wild we don’t even know about,” according to D’Angelo.
One question that’s still unanswered is why the fawns were conjoined.
“Even in humans we don’t know,” D’Angelo said. “We think it’s an unnatural splitting of cells during early embryo development.”
The Minnesota Department of Natural Resources will have the fawns on display — in stuffed form — at their headquarters in St. Paul. The University of Minnesota Veterinary Anatomy Museum will have a skeletal display, researchers said.