Four new California lizard species have been described in a new scientific paper published last week, and a couple of them were hiding in plain sight.
The new species are all legless lizards. Formerly considered members of the wide-ranging species Anniella pulchra, the lizards are different enough in skeletal structure, scale patterns and color, say the paper's authors, to deserve assignment to their own distinct species.
Given that Anniella pulchra was already rare enough despite its extensive range to concern conservationists before being split up into five species, the herpetologists say that the new species probably deserve close scrutiny by wildlife protection agencies.
Often taken for snakes by people lucky enough to happen upon them, legless lizards are actually not all that closely related to those better-known limbless reptiles. It's yet another example of convergent evolution: given an environment in which legs get in the way, such as burrowing through sand or other loose soils, quite a few lizard species have lost their legs. Unlike snakes, though, many legless lizards have functioning eyelids and external ears. Snakes' transparent eyelids are fused shut permanently, and though they still have inner ear organs, they're completely enclosed.
Also unlike snakes, California legless lizards retain the ability to jettison their tails to distract potential predators. That's a trait that comes in handy, as quite a few small predators eat legless lizards, from dainty little ringneck snakes to thrashers, deermice, and loggerhead shrikes. A temptingly quivering tail can often provide enough of a lure to give a legless lizard time to burrow for cover while its would-be predator is occupied.
With their tails still on, California legless lizards tend to be about 8-10 inches long at maturity, and slender enough that they might pass for very large worms at first glance. As far as we know, all the new species of legless lizard share pretty much the same lifestyle, hiding in loose, sandy soils and feeding on insect larvae and eggs, small beetles and spiders, and the occasional termite. Their habit of avoiding direct sun means they're much less likely than other California lizards to be spotted by casual observers: you pretty much have to be looking for a California legless lizard to find one, though they sometimes do show up beneath piles of debris or trash along with slender salamanders.
That only happens where there's a bit of available moisture. Arid environments aren't welcoming for legless lizards, and the genus Anniella tends to stick to the outermost edges of California's deserts, at springs or other places where more moisture than usual leaks over the fringing mountains.
In the paper, published in the September 16 issue of the Harvard University Museum of Comparative Zoology's journal Breviora, Theodore Papenfuss of UC Berkeley and James Parham of CSU Fullerton break up old Anniella pulchra, which had been considered to range throughout Central and Southern California into Baja, into two wide-ranging species and three more of very restricted distribution. The lizards in the northernmost part of the range from the Santa Barbara coast to just east of the Bay Area are still called Anniella pulchra, as are the lizards that occupy the foothills of the mountains that fringe the western Antelope Valley.
Most of the legless lizards in the southern half of the old species' range are now part of the new species Anniella stebbinsi, which resembles its northern cousin in almost every visible respect -- yellow belly, 77 vertebrae, and one lateral stripe on each side rather than a pair -- but which has an extra pair of chromosomes compared to Anniella pulchra. This species, named for UC Berkeley's Bob Stebbins -- the dean of living California herpetologists and an all-around wonderful human being -- extends down into Baja California and has an isolated northern population in the Tehachapi and Piute mountains at the southern end of the Sierra Nevada.
The Stebbins' legless lizard has gotten a bit of extra press attention this week in the wake of Papenfuss and Parham's paper, with stories trumpeting the headline "new lizard species discovered at LAX." That's not precisely wrong, but it is a little bit misleading. There've long been undocumented reports of legless lizards in the El Segundo Dunes near LAX, which Papenfuss confirmed when he collected one there in 2010. And the lizard he collected there has been assigned the role of holotype for the new species: it's the example future herpetologists will refer to when they discuss the species.
But it wasn't so much that a new species was discovered at the El Segundo Dunes; it's more accurate to say that a very large group of lizards stretching from Lake Isabella to Lazaro Cardenas, Mexico that had long been mentioned as a potential new species has in fact been described as one, with an individual from El Segundo Dunes being chosen as an utterly typical example of that new species.
Of course, that doesn't make as short and punchy a headline.
The three other new legless lizard species offer better examples of local "discovery," though they've been eyed as possible new species for a few years as well. There's Anniella grinnelli, the Bakersfield legless lizard, which lives in and around its eponymous city, and is named for pioneering California biologist Joseph Grinnell; Anniella alexandrae, the Temblor Legless Lizard, known from just two sites between McKittrick and Taft in Kern County and named for the fascinating Annie Alexander; and Anniella campi, the Southern Sierra legless lizard, known from just three springs along the base of the mountains on the edge of the Mojave Desert in Kern and Inyo counties. That one's named for UC Berkeley paleontologist Charles Camp, best known for discovering the ichthyosaurs at Berlin-Ichthyosaur State Park in Nevada.
Clearly, the naming of these new species is a field day for honoring the pantheon of biologist elders from UC Berkeley. But the new species are also a warning about what we might lose in developing more of the California landscape without paying close attention to what's living there. The three Mojave Desert springs that harbor the entire known global population of Anniella campi are vulnerable to off-road vehicle use, energy development, and desiccation due to climate change. Just a couple of ill-considered road projects or a few stray head of cattle could have wiped the species out before we knew it existed.
It's a lesson we keep learning over and over again in California: the closer we look at the living landscape, the more new species we find. Sometimes they're in places well off the trodden path, and other times they're right under our noses; in city parks, under trash heaps, or hanging on next to the sixth-busiest airport in the world.
TrackBack URL: http://www.kcet.org/cgi-bin/mt/mt-tb.cgi/20812