Very local in humid evergreen forest of limestone (karst) lowlands and foothills in southernmost Veracruz and adjacent Chiapas; endemic. Stays on or near the ground, moving quickly over and among limestone boulders, popping in and out of caves and crevices. Like most wrens, heard more often than seen, but can be curious; sometimes appears at close range, bobbing and holding its tail cocked. Distinctive: rather chunky with a very long bill and a whitish bib.