Epioblasma flexuosa (Rafinesque, 1820)

Arcuate pearly mussel, Leafshell, Northern leafshell



Taxonomy & Nomenclature

Synonym/s: Obliquaria (Quadrula) flexuosa Rafinesque, 1820 (original combination); Obliquaria (Quadrula) flexuosa Rafinesque, 1820; Obliquaria (Quadrula) flexuosa var. bullata Rafinesque, 1820; Unio foliatus Hildreth, 1828; Unio flexuosus Rafinesque, 1820; Margarita (Unio) foliatus Hildreth, 1828; Margaron (Unio) foliatus Hildreth, 1828; Dysnomia flexuosa Rafinesque, 1820; Truncilla (Dysnomia) foliata Hildreth, 1828; Dysnomia (Dysnomia) flexuosa Rafinesque, 1820; Plagiola (Epioblasma) flexuosa Rafinesque, 1820


Conservation Status


Last record: 1900

IUCN RedList status: Extinct



Alabama, Illinois, Indiana, Kentucky, Ohio and Tennessee, USA


Biology & Ecology




Lectotype: ANSP 20249 (male, selected by Johnson & Baker, 1973:155)

Type locality: Kentucky River


Other specimens:

ANSP 56571 (female, type of Unio foliatus Hildreth, 1828)
INHS 1747
INHS 4379
INHS 4751
INHS 4779
INHS 5922
INHS 6034
INHS 6726
INHS 23078
INHS 24132
INHS 25209
INHS 28711
INHS 28955
INHS 32709
INHS 41696
INHS 41708








Original scientific description:

Rafinesque, C. S. (1820). Monographie des coquilles bivalves fluviatiles de la Rivière Ohio, contenant douze genres et soixante huit espèces. Annales Generales des Sciences Physique, bruxelles 5: 287-322.


Other references:

Baillie, J. and Groombridge, B. (eds). 1996. 1996 IUCN Red List of Threatened Animals. pp. 378. International Union for Conservation of Nature, Gland, Switzerland and Cambridge, UK.

Bogan, A. E. (2000a). Epioblasma flexuosa. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. ( Downloaded on 22 April 2012.

Bogan, A.E. (Mollusc Specialist Group). 2000b. Epioblasma flexuosa. The IUCN Red List of Threatened Species 2000: e.T7868A12859429. Accessed on 19 June 2022.

Cicerello, R.R. and G.A. Schuster. 2003. A guide to the freshwater mussels of Kentucky. Kentucky State Nature Preserves Commission Scientific and Technical Series 7:1-62.

Cowie, Robert H., Régnier, Claire, Fontaine, Benoît, and Bouchet, Philippe. (2017). Measuring the Sixth Extinction: what do mollusks tell us? The Nautilus 131(1): 3-41.

Graf, Daniel L. and Cummings, Kevin S. (2021). A ‘big data’ approach to global freshwater mussel diversity (Bivalvia: Unionoida), with an updated checklist of genera and species. Journal of Molluscan Studies 87(1): eyaa034.

Groombridge, B. (ed.). 1994. 1994 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland and Cambridge, UK.

Haag, Wendell R. (2009). Past and future patterns of freshwater mussel extinctions in North America during the Holocene, pp. 107-128. In: Turvey, Samuel T. (ed.). Holocene Extinctions. Oxford, UK & New York, USA: Oxford University Press. xii + 352 pp.

Hildreth, S. P. (1828). Observations on, and descriptions of the shells found in the waters of the Muskingum River, Little Muskingum, and Duck Creek, in the vicinity of Marietta, Ohio. American Journal of Science and Arts 14(2): 276–291. [description of E. foliatus, a junior synonym of E. flexuosa]

Hilton-Taylor, C. 2000. 2000 IUCN Red List of Threatened Species. IUCN, Gland, Switzerland and Cambridge, UK.

IUCN. 1990. IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland and Cambridge, UK.

Johnson, R.I. 1978. Systematics and zoogeography of Plagiola (= Dysnomia = Epioblasma), an almost extinct genus of freshwater mussels (Bivalvia: Unionidae) from middle North America. Bulletin of the Museum of Comparative Zoology, 148(6): 239-320.

Johnson, R. I. and Baker, H. B. (1973). The types of Unionacea (Mollusca: Bivalvia) in the Academy of Natural Sciences of Philadelphia. Proceedings of the Academy of Natural Sciences of Philadelphia 125: 145–186.

Mirarchi, R.E. 2004. Alabama Wildlife. Volume One: A Checklist of Vertebrates and Selected Invertebrates: Aquatic Mollusks, Fishes, Amphibians, Reptiles, Birds, and Mammals. University of Alabama Press: Tuscaloosa, Alabama. 209 pp.

NatureServe. (2014). NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available (Accessed: January 28, 2015).

Parmalee, P.W. and A.E. Bogan. 1998. The Freshwater Mussels of Tennessee. University of Tennessee Press: Knoxville, Tennessee. 328 pp.

Régnier, Claire, Fontaine, Benoît and Bouchet, Philippe. (2009). Not Knowing, Not Recording, Not Listing: Numerous Unnoticed Mollusk Extinctions. Conservation Biology 23(5): 1214-1221.

Stansbery, D.H. 1976. Naiad mollusks. Pages 42-52 in H. Boschung (ed.). Endangered and threatened plants and animals of Alabama. Bulletin of the Alabama Museum of Natural History 2:1-92.

Watters, G.T. 1995. A field guide to the freshwater mussels of Ohio. revised 3rd edition. Ohio Department of Natural Resources, Division of Wildlife, Columbus, Ohio. 122 pp.

Watters, G. Thomas, Hoggart, Michael A. and Stansbery, David H. (2009). The Freshwater Mussels of Ohio. Columbus, Ohio: Ohio University Press, 421 pp.

Wells, S.M., Pyle, R.M. and Collins, N.M. (compilers) 1983. The IUCN Invertebrate Red Data Book. IUCN, Gland, Switzerland and Cambridge, UK.

Williams, James D., Bogan, Arthur E., Butler, Robert S., Cummings, Kevin S., Garner, Jeffrey T., Harris, John L., Johnson, Nathan A. and Watters, G. Thomas. (2017). A revised list of the freshwater mussels (Mollusca: Bivalvia: Unionida) of the United States and Canada. Freshwater Mollusk Biology and Conservation 20: 33-58.

Williams, J.D., A.E. Bogan, and J.T. Garner. (2008). Freshwater mussels of Alabama and the Mobile basin of Georgia, Mississippi, and Tennessee. Tuscaloosa: University of Alalbama Press, 908 pp.

Vanatta, E. G. (1915). Rafinesque’s types of Unio. Proceedings of the Academy of Natural Sciences of Philadelphia 67: 549–559.


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