(CNN) -- They live at the end of a runway at one of the nation's busiest airports, and only now has anyone cared to identify them and even give them a name.
They are yellow-bellied legless lizards, and their species name is A. stebbinsi, after 98-year-old herpetologist Robert C. Stebbins. Their home is in the dunes west of Los Angeles International Airport.
Stebbins' namesakes, which look like snakes, were discovered and identified by Theodore Papenfuss, a herpetologist with the Museum of Vertebrate Zoology at the University of California, Berkeley, and James Parham of California State University, Fullerton.
The pair also reported finding three other new species of legless lizards, all from California, in research published this week in the journal Breviora from the Museum of Comparative Zoology at Harvard University.
The other legless lizards were found among oil derricks in the San Joaquin Valley, on the edge of the Mojave Desert and in a vacant lot in downtown Bakersfield.
"These are animals that have existed in the San Joaquin Valley, separate from any other species, for millions of years, completely unknown," Parham said in a statement from UC Berkeley.
Papenfuss said, "This shows that there is a lot of undocumented biodiversity within California."
Undocumented because it's hard to find, at least in the case of these lizards. They burrow into the loose soil and spend their entire lives in an area measured in square feet.
The A. stebbinsi were found under leaf litter. The three other species -- the silver-bellied A. alexanderae, the purple-bellied A. grinnelli and the yellow-bellied A. campi -- were found after researchers left flattened cardboard boxes and pieces of plywood in areas where they suspected the lizards might live, then went back to see if the critters took up residence underneath.
And this was no quick study. The specimens were collected over a 14-year period, the researchers said. In fact, the researchers reported that all of the species were actually in collections and stored in alcohol.
The alcohol, however, removed coloring so scientists had to do genetic testing to confirm that those specimens were part of the previously unidentified species.
The four new species bring to five the number of known legless lizard species in California. The previously identified common legless lizard of Northern California looks like the A. stebbinsi, and the two can only be distinguished by genetic testing, the researchers said.
There are more than 200 species of legless lizards worldwide, they said.
And you must be wondering how to tell a legless lizard from a snake.
According to the Natural History Museum of Los Angeles County, the easiest way to tell the difference is to look them in the eyes. If they blink, they're lizards. If not, they're snakes. That's because lizards have eyelids and snakes don't.