taxonID	type	description	language	source
F5F475F674C1527CA9ECD4B75BAFC3AD.taxon	etymology	Etymology. obscura from English “ obscure ” in reference to the species evading discovery until the present study.	en	Perkins, Michael A., DeVilbiss, Katharine L., Whelan, Nathan V., Hoch, Rachael A., Jones, Brena K., Mays, Jason W., Evans, Heather K., Benfield, Sierra B. (2025): A new endemic freshwater mussel (Bivalvia, Unionidae) genus and species, Ligodonta obscura, from the Yadkin-Pee Dee River drainage in North Carolina, USA. ZooKeys 1248: 245-265, DOI: 10.3897/zookeys.1248.152952
F5F475F674C1527CA9ECD4B75BAFC3AD.taxon	diagnosis	Diagnosis. Shell morphology (Figs 3 – 6, 10). Shell small, thin, subovate, and moderately inflated; umbo extending slightly beyond the hinge line, with single or weakly double-looped beak sculpture in younger individuals; hinge weak. Anterior laterally compressed; anterior margin strongly rounded towards ventral margin. Ventral margin straight. Posterior margin broadly rounded, higher than umbo distally. Posterior ridge weakly pronounced, rounded, double. Periostracum somewhat thin, papery, appearing dark brown in most individuals; surface with fine, minor growth lines. The following color description was aided by backlight (Fig. 3 D, H): periostracum interrupted by dark concentric growth rings, base color yellow or light brown, anterior with variably spaced dark green or brown rays. Nacre diaphanous, somewhat iridescent with blue or cream tint. Umbo cavity shallow. Anterior adductor scar well defined; posterior adductor scar weak. In the left valve, a single, small, smooth, laterally-compressed pseudocardinal tooth extending to a weak interdental projection, oriented directly above the umbo cavity and parallel to the hinge line. Left lateral tooth absent, appearing as a weakly inflated ridge. In the right valve, a single small, rounded, laterally compressed, triangular pseudocardinal tooth oriented anterior to the umbo cavity and parallel to the anterior margin. Right lateral tooth as described above. No obvious sexual dimorphism in shell morphology. General external characteristic measurements as follows (n = 14): shell length = 23.2 mm min – 46.2 mm max, x ̄ = 35.9 mm; shell height = 14.6 mm min – 26.3 mm max, x ̄ = 20.7 mm; shell width 7.3 mm min – 17.5 mm max, x ̄ = 13.8 mm; ratios from averages as follows: length 1.73 times height and 2.59 times width, height 1.5 times width. Soft anatomy (Figs 4 B, F, 7). Incurrent and excurrent apertures approximately equal in length, separated by thin mantle bridge. Excurrent aperture lacking papillae, smooth or weakly crenulate, dark gray to dark brown, occasionally with irregular cream-colored stripes. Incurrent aperture papillae present, simple or sometimes bifurcate anteriorly, dark gray to dark brown at base and cream-colored to tan distally (Fig. 7). Posterior margin of mantle pigmented, appears as a thin, dark band anterior to apertures. Inner lamellae of gills fully attached to visceral mass; outer gills marsupial. Foot tissue pale pink-orange. Glochidia (Fig. 8 B – E). Larvae subtriangular (Hoggarth 1999); length approximately 300 – 350 µm; dorsal margin straight, ventral margin rounded, valves convex; apical styliform hooks present and conspicuous, approximately 50 µm in length and not strongly recurved, mesial surface of hooks with scattered microstylets. Occasionally appearing with a red tint. Charged gills in brooding females pink.	en	Perkins, Michael A., DeVilbiss, Katharine L., Whelan, Nathan V., Hoch, Rachael A., Jones, Brena K., Mays, Jason W., Evans, Heather K., Benfield, Sierra B. (2025): A new endemic freshwater mussel (Bivalvia, Unionidae) genus and species, Ligodonta obscura, from the Yadkin-Pee Dee River drainage in North Carolina, USA. ZooKeys 1248: 245-265, DOI: 10.3897/zookeys.1248.152952
F5F475F674C1527CA9ECD4B75BAFC3AD.taxon	distribution	Distribution. Ligodonta obscura is a rare mussel with an extraordinarily narrow distribution currently known from only two streams in central North Carolina, USA (Fig. 1). A total of 43 live individuals were observed in 2016 – 2022 from one contiguous 7.15 km reach in Little River, a direct tributary on the eastern edge of the Pee Dee River in Randolph County. Historical collections are represented by only three specimens at NCSM from an approximately 6 km reach of Barnes Creek, a tributary draining to the Uwharrie River (a major tributary to the Pee Dee River) in Montgomery County, NC. Despite intensive surveys, no live specimens have been recovered from Barnes Creek since 2010, but the species may continue to persist. Ligodonta obscura is not currently known from any other locations locally or globally, nor is the species known to be represented in additional museum collections.	en	Perkins, Michael A., DeVilbiss, Katharine L., Whelan, Nathan V., Hoch, Rachael A., Jones, Brena K., Mays, Jason W., Evans, Heather K., Benfield, Sierra B. (2025): A new endemic freshwater mussel (Bivalvia, Unionidae) genus and species, Ligodonta obscura, from the Yadkin-Pee Dee River drainage in North Carolina, USA. ZooKeys 1248: 245-265, DOI: 10.3897/zookeys.1248.152952
268073B09146544E972E565C764967A0.taxon	type_taxon	Type species. Ligodonta obscura Perkins, DeVilbiss & Whelan, 2025, sp. nov.	en	Perkins, Michael A., DeVilbiss, Katharine L., Whelan, Nathan V., Hoch, Rachael A., Jones, Brena K., Mays, Jason W., Evans, Heather K., Benfield, Sierra B. (2025): A new endemic freshwater mussel (Bivalvia, Unionidae) genus and species, Ligodonta obscura, from the Yadkin-Pee Dee River drainage in North Carolina, USA. ZooKeys 1248: 245-265, DOI: 10.3897/zookeys.1248.152952
268073B09146544E972E565C764967A0.taxon	diagnosis	Diagnosis. Monotypic, see species Diagnosis below.	en	Perkins, Michael A., DeVilbiss, Katharine L., Whelan, Nathan V., Hoch, Rachael A., Jones, Brena K., Mays, Jason W., Evans, Heather K., Benfield, Sierra B. (2025): A new endemic freshwater mussel (Bivalvia, Unionidae) genus and species, Ligodonta obscura, from the Yadkin-Pee Dee River drainage in North Carolina, USA. ZooKeys 1248: 245-265, DOI: 10.3897/zookeys.1248.152952
268073B09146544E972E565C764967A0.taxon	etymology	Etymology. Greek, ligo - meaning “ little ” and - donta meaning “ tooth. ”	en	Perkins, Michael A., DeVilbiss, Katharine L., Whelan, Nathan V., Hoch, Rachael A., Jones, Brena K., Mays, Jason W., Evans, Heather K., Benfield, Sierra B. (2025): A new endemic freshwater mussel (Bivalvia, Unionidae) genus and species, Ligodonta obscura, from the Yadkin-Pee Dee River drainage in North Carolina, USA. ZooKeys 1248: 245-265, DOI: 10.3897/zookeys.1248.152952
