Plaintiff alleges government agency failed in protecting endangered species

The Center for Biological Diversity has taken legal action against the U.S. Fish and Wildlife Service, accusing it of failing to protect a rare species. The complaint was filed on December 18, 2025, in the United States District Court for the District of Arizona, Tucson Division, against the U.S. Fish and Wildlife Service and its Director Brian Nesvik, as well as Doug Burgum in his capacity as Secretary of the U.S. Department of the Interior.

The lawsuit centers around the Ellett Valley millipede, a species threatened by urban development and environmental changes in its native Virginia habitat. The Center for Biological Diversity claims that the U.S. Fish and Wildlife Service violated the Endangered Species Act (ESA) by not issuing a timely “90-day finding” on their petition to list this millipede as endangered or threatened. According to the ESA, such a determination should have been made within 90 days of receiving the petition to ensure prompt protection measures are considered for at-risk species.

Camila Cossio and Brian Segee, attorneys from the Center for Biological Diversity, argue that this delay jeopardizes crucial protections needed for the survival of this unique cave-dwelling creature. They highlight that without these protections, urban expansion and infrastructure projects like pipelines could further threaten the millipede’s limited habitat range. The plaintiffs are seeking declaratory and injunctive relief from the court to compel the U.S. Fish and Wildlife Service to issue their findings promptly.

The case underscores ongoing tensions between conservation efforts and developmental pressures. It also raises questions about governmental accountability in adhering to environmental laws designed to prevent species extinction. By pursuing this lawsuit, the Center aims not only to secure immediate action for the Ellett Valley millipede but also to set a precedent ensuring timely responses from federal agencies on similar conservation petitions.

Representing their cause are attorneys Camila Cossio and Brian Segee from Oregon and California respectively, with both awaiting Pro Hac Vice admission pending in Arizona’s jurisdiction. The case is identified under Case No: 4:25-cv-00701-LCK with no specific judge named yet.