SAN DIEGO (CBS 8) - Scientists are excited by a rare find off the coast of Mexico -- the body of conjoined twin gray whales.
Other types of conjoined whales and dolphins have been discovered before, but this could be the first documented case of conjoined gray whales.
"You can see the animal has two tails, one for each twin. And then also each of them have their own head and they're joined at the abdomen," NOAA research biologist Kerri Danil said.
A video showing the whales posted on YouTube was taken Sunday in Mexico's Scammon's Lagoon along the Baja California peninsula, where scientists found the carcass.
"What was going on… it was probably really confusing to them when they first saw it," Danil said.
She says conjoined twins have been documented in dolphins and different baleen whales, but never the gray whale.
"I haven't found any documentation in the literature for gray whales, so this might be the first," she said.
Photos and comments posted on Facebook reveal the carcass was about seven feet in length, which is only about half the size of a healthy calf. Danil says scientists should be able to determine if it was stillborn.
"You can look at the tissues to tell whether or not the animals ever took a breath of air, so they'll be able to tell whether it was a still birth or whether the animals actually surfaced afterwards and lived for some time possibly," she said.
And if born alive, Danil says it's not likely the conjoined twins lived for long. The orientation of the calves would have made breathing and swimming a big challenge.
"They're in the wrong position for swimming… they're joined abdomen to abdomen… if the animal was oriented this way it would be very hard for them to swim," Danil said. "It is sad, but it's a part of life and there's so much you can learn from them."
Twin births are so rare among whales, researchers say there has been only one documented successful case: a beluga whale in captivity. One calf was born alive, the other was born dead.