The conjoined twins—also known as Siamese twins—measured about seven to ten feet (two to three meters) in length, according to several reports. That's shorter than the usual 12- to 16-foot (3.6- to 4.8-meter) length of full-term gray whale calves.

Gray whale gestation lasts for 13.5 months, said Jim Dines, collections manager of mammals at the Natural History Museum of Los Angeles County in California. So the conjoined twins were probably between 8.5 and 10.5 months of age when they were born, he noted.

Dines cautions that those ages are only estimates based on the lengths of single fetuses. "In the case of twins, the mother