Eurynia dilatata

Eurynia was elevated from synonymy by Campbell and Lydeard (2012) to accommodate Elliptio dilatata, which consistently falls outside the Elliptio clade in molecular analyses (see also Perkins et al. 2017) (Williams et al. 2017).

Williams et al. (2017) largely retain the classification of Turgeon et al. (1998) with some exceptions. They note note that phylogenetic affinities remain unknown for most species that are currently recognized under Elliptio and some may prove to be members of other genera (e.g., Eurynia; Elderkin et al. 2008; Campbell and Lydeard 2012).

This species is widespread in the eastern U.S., occurring throughout much of the Mississippi River system, and portions of the Great Lakes drainage and can often be abundant at given sites.

This species is widespread in the eastern U.S., occurring throughout much of the Mississippi River system, and portions of the Great Lakes drainage (Mirarchi et al., 2004). Distribution includes the entire Mississippi River drainage from the St. Lawrence River and its tributaries south to northern Louisiana and west to the tributaries of the Red River, Oklahoma (Parmalee and Bogan, 1998). In Canada, it is common in the Great Lakes and their tributaries from Lake Michigan to Lake Erie, uncommon in Lake Ontario and the St. Lawrence River (Clarke, 1981).

In Minnesota, it is in the Minnesota, St. Croix, and Mississippi River drainages, and some southern streams (Sietman, 2003). In Kentucky, it is generally distributed statewide (Cicerello and Schuster, 2003; Clark, 1988; Gordon, 1991). In Tennessee, it is in most small streams and large rivers throughout E and middle Tennessee, from the upper Clinch and Powell Rivers in the E to the Stones, Elk, and Duck Rivers in the center (Parmalee and Bogan, 1998). It occurred in the Tennessee River across northern Alabama historically including some large tributaries but is extant only in Guntersville and Wilson Dam tailwaters (possibly Paint Rock River- Ahlstedt, 1996) (Williams et al., 2008). In Mississippi, it is in the Mississippi River N and Yazoo drainages (Jones et al., 2005). In Texas, it is questionable (some confusion with Fusconaia mitchelli) from the San Marcos River (Howells et al., 1996). Oklahoma distribution: Kiamichi, Neosho, and the Poteau Rivers (Branson, 1983), however likely extirpated from the Poteau (White, 1977). It was recently found in the Little River, Oklahoma (Vaughn and Taylor, 1999); Poteau (Vaughn and Spooner, 2004), historically in Kiamichi (Vaughn, 2000). In Kansas, it is extant in the Spring River (Branson, 1966- also MO) and Marais des Cygnes and Neosho River basins with archaeological specimens from as far NW as the Republican River in Geary Co. (Kansas drainage) (Couch, 1997). In Wisconsin, it is fairly widespread and abundant, especially the N and E (Mathiak, 1979). In Illinois, it is generally distributed in five drainages (Fox River, Kankakee-Iroquois River, Vermillion and Maxon River, Sangamon, Kaskaskia River, Little Wabash and Bonpas Creek) where it is uncommon to rare (Cummings and Mayer, 1997; Schanzle and Cummings, 1991; Sietman et al., 2001); recently the Fox River basin in Illinois and Wisconsin where it was uncommon (a few occurrences in Illinois and one in Wisconsin) (Schanzle et al., 2004). Indiana distribution: Blue (Sietman et al., 1995), Tippecanoe (Cummings and Berlocher, 1990), East Fork White (Harmon, 1992), Muscatatuck (Harmon, 1989), St. Joseph and Maumee (Pryor, 2005). In Ohio, it is very widespread and common throughout most of the state (Watters, 1992; 1995; Lyons et al., 2007; Grabarciewicz, 2008; Watters et al., 2009). It is widely distributed and common in the Middle and Upper New River drainages in Virginia (Pinder et al., 2002); and New (Jirka and Neves, 1990) and Kanawha (Morris and Taylor, 1992) Rivers in West Virginia; also Copper Creek (Fraley and Ahlstedt, 2000; Hanlon et al., 2009); upper S Fork Holston (Stansbery and Clench, 1978), and upper Clinch River (historical) (Jones et al., 2005), Virginia. In North Carolina, it is known from the Hiwassee, Little Tennessee, French Broad, and New River Basins (Bogan, 2002) in Allegheny, Ashe, Cherokee, Macon, Swain, and Watauga Cos. (LeGrand et al., 2006). In Louisiana, Vidrine (1993) reports it from NE drainages. It was recently collected from 12 of 38 sites surveyed in the Tonawanda Creek basin (Niagara River drainage) in western New York (Marangelo and Strayer, 2000). It occurs in the Ouachita (Posey et al., 1996), Cache and White Rivers, Arkansas (Christian, 1995; Gordon, 1982; Gordon et al., 1994). It is also known from the Clinton River drainage in Michigan (Trdan and Hoeh, 1993; Strayer, 1980) and lower Michigan to upper peninsula (Goodrich and Van der Schalie, 1939) in Lakes Michigan, Huron, St. Clair basins (Badra and Goforth, 2003). In Canada, it is known from Ontario (incl. Sydenham- Metcalfe-Smith et al., 2003) with several secure populations and Quebec which has fewer populations that are in decline (Metcalfe-Smith and Cudmore-Vokey, 2004). Recently only dead shells were found in surveys of the Marais des Cygnes, Elk, and Fall Rivers in Kansas (Combes and Edds, 2005). Specimens from the Black River (St. Clair drainage), Michigan, were relocated to the Detroit River in 1992 (Trdan and Hoeh, 1993).