Almost by accident:
Doctors don’t regularly come across undiscovered bits of human anatomy, but a team of physicians recently reported a never-before-described set of salivary glands in patients’ necks…
According to Vogel, there are likely two main reasons the tubarial glands haven’t been found before: researchers had not previously used PSMA PET/CT to look for salivary glands, and the newly discovered glands are located in a region that’s hard to access with standard surgical procedures. “With the other salivary glands, you can just feel them by either with your hand or see them during surgery,” Vogel explains. “The location we’re describing now, you can only see it with a nasal endoscopy.” Nasal endoscopy is a method in which a tube with a tiny camera and light are used to image the nose and sinuses. Based on the tubarial glands’ similarities to the volume and draining system of the sublingual gland—one of the three major salivary glands—the authors suggest that the new glands should be classified as a fourth major gland. However, they also note that some might disagree with this categorization, because the new glands share similarities with minor glands as well.
Diana Kwon, “Scientists Discover New Human Salivary Glands” at The Scientist
Paper. (open access)
Because no one knew these glands existed, we haven’t had to hear a lot of just-so stories about how they evolved. Evolutionary biologists will need to make up for the lost time … 😉