CORPUS CHRISTI, Texas— The Center for Biological Diversity sued the U.S. Fish and Wildlife Service today for waiting more than 16 years to make a timely decision on whether the Tamaulipan spot-tailed earless lizard should be protected under the Endangered Species Act.

In the U.S. this lizard survives in only a few widely separated populations in South Texas, including Nueces, Jim Wells, Val Verde and Kinney counties.

“This little Texas lizard has quietly slipped toward extinction while the Fish and Wildlife Service sat on its hands, so we’re determined to push for action,” said Hayden Wyatt, an associate attorney at the Center for Biological Diversity. “The Endangered Species Act requires timely decisions to prevent exactly this kind of slow-motion disappearance. Every year of delay increases the risk that this unique lizard will be lost forever.”

These small, elusive lizards are found in semi-arid to humid grasslands of southern Texas and northern Mexico, where they depend on native grasslands and healthy soils to survive. Once far more widespread, the Tamaulipan spot-tailed earless lizard has been reduced to just a handful of fragmented populations and faces mounting threats from habitat loss, land-use conversion and climate change.

In January 2010, conservationists petitioned the Fish and Wildlife Service to list the spot-tailed earless lizard under the Endangered Species Act. The agency acknowledged in 2011 that the petition presented substantial information indicating that listing may be warranted. Despite this finding — and despite later formally recognizing the Tamaulipan spot-tailed earless lizard as a separate species — the Service has failed to complete the legally required 12-month status review for more than 16 years.

The lizard was long considered a subspecies of the Plateau spot-tailed earless lizard, but recent scientific research has confirmed it is a distinct species, with its own evolutionary history and conservation needs.

The species’ decline is driven largely by widespread habitat destruction and degradation. Native grasslands have been converted to agriculture and development, while remaining habitats are increasingly compromised by brush encroachment, invasive plants and altered soil conditions. Climate change poses an additional existential threat, with modeling predicting the loss of all suitable habitat in parts of the lizard’s current range.

“The science is clear that this lizard is in serious trouble,” Wyatt said. “What’s missing is legal protections to stop its steep decline.”

The Endangered Species Act requires the Fish and Wildlife Service to make prompt decisions on petitions to list species as endangered or threatened so that imperiled wildlife can receive timely protections.

The Tamaulipan spot-tailed earless lizard’s future could be threatened by a recent Trump administration decision to strip species of protections for the places where they live. The Center and other conservation groups recently sued over the attempt to roll back habitat protections, which will leave imperiled species at even greater risk of going extinct.