Archaeological Data Indicate a Broader Late Holocene Distribution

Archaeological Data Indicate a Broader Late Holocene Distribution of the Sandbank Pocketbook (Unionidae: Lampsilis satura Lea 1852) in Texas Author(s): Steve Wolverton and Charles R. Randklev Source: American Malacological Bulletin, 34(2):133-137. Published By: American Malacological Society DOI: http://dx.doi.org/10.4003/006.034.0209 URL: http://www.bioone.org/doi/full/10.4003/006.034.0209 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Amer. Malac. Bull. 34(2): 133–137 (2016) RESEARCH NOTE Archaeological Data Indicate a Broader Late Holocene Distribution of the Sandbank Pocketbook (Unionidae: Lampsilis satura Lea 1852) in Texas Steve Wolverton1 and Charles R. Randklev2 1Department of Geography and the Environment, University of North Texas, Denton, TX 76203, U.S.A. 2Institute of Renewable Natural Resources, Texas A&M University, College Station, TX 77843, U.S.A. Correspondence Steve Wolverton: [email protected] Abstract: One way that archaeologists provide unique conservation datasets is through the establishment of pre-Euroamerican baselines for animal communities that were part of human-environment interactions during the last few millennia. Freshwater mussel remains from archaeological sites offer a rich data source for establishing this type of baseline. We establish a conservation baseline for the late Holocene sandbank pocketbook (Lampsilis satura, Lea 1852) in the upper Trinity River of central and north Texas. These data may 1) lead to greater confi dence in existing contemporary data for unoinid biogeography; 2) lead to information on whether or not community composition differs between the late Holocene and today; and/or 3) provide a justifi cation for more intensive contemporary surveys. Such data are relatively easily acquired, inexpensive to generate, and highly informative for environmental management. Key words: applied zooarchaeology, paleobiogeography, archaeomalacology, Unionidae Archaeological remains of mussel shell are increasingly understood depending on geographic location. This is unfortu- studied for the purpose of understanding the late Holocene nate, as these types of data are equally critical for evaluating a geographic ranges of unionids (e.g., Randklev et al. 2010a, species’ status; the absence of such information may hamper Peacock et al. 2012, Randklev and Lundeen 2012). The use of efforts to evaluate a species’ viability or lead to erroneous conclu- archaeological data on animal remains in conservation biol- sions about its range curtailment (Randklev and Lundeen 2012). ogy is termed “applied zooarchaeology” as zooarchaeology is In the Upper Trinity River drainage, located in north the study of whole and fragmented bones, shells, antlers, and central Texas, the late Holocene biogeography of unionids other animal tissues recovered from archaeological sites (Lyman continues to be poorly understood; several species thought to 1996, Wolverton and Lyman 2012). Such data provide a pre- be rare or absent have been identifi ed in archaeological samples Euroamerican baseline for biological conservation and eco- that date to the late Holocene (Randklev and Lundeen 2012). logical restoration (Lyman 2012a, Rick and Lockwood 2013, Shell remains for one of these species, the sandbank pocket- Wolverton et al. 2016a). book (Lampsilis satura, Lea 1852), are particularly important, as Knowledge of the distribution and status of threatened until recently this species was thought to have never occurred freshwater mussel species is one of the most important compo- in the Trinity River (Howells 2010). Unlike rivers in the nents for mussel conservation efforts (NNMCC 1998). Although American Midwest and Southeast, rivers in Texas and many studies on mussels are increasing, information on the geographic other areas of the interior Southwest tend to be hydrologi- distribution and location of remaining mussel populations var- cally and geographically isolated, generally winding north to ies by species, location, and perceived rarity. For example, in south from their headwaters to their mouths in the Gulf of Texas mussels have been largely ignored by the scientifi c and Mexico. As result, each river system comprises regionally iso- conservation community until the recent listing of 15 species as lated unionid and fi sh host communities. Establishing the state-threatened, of which 12 are being considered for listing biogeographic presence of one or more species in a river such under the Endangered Species Act (TPWD 2010, USFWS 2001, as the Trinity represents an important range extension across 2011). Since then researchers have rediscovered several species drainages that are hydrologically independent. Such a range thought to have been extinct (Randklev et al. 2010b, Randklev extension may be minor in terms of geographic distance, but is et al. 2012) and uncovered additional populations of rare species signifi cant in terms of hydrology and unionid biogeography. (Randklev et al. 2013, Ford et al. 2014, Tsakiris and Randklev A single live individual and a weathered shell, both tenta- 2016). Similarly, knowledge of the historical distribution of tively identifi ed as Lampsilis satura, were recently reported mussels varies from being well documented to poorly from the upper Trinity River drainage (McDermid et al. 2013, 133 134 AMERICAN MALACOLOGICAL BULLETIN 34 · 2 · 2016 Ford et al. 2014) Historically, Lampsilis satura occurred from thick-shelled and are characterized by beaks that are raised the San Jacinto east into the Neches-Angelina and Sabine high above the hinge line with a posterior ridge that is broadly Rivers (Howells 2010a). L. satura inhabits small to large rivers rounded. Also important is the presence of muscle scars along with moderate fl ows on gravel, gravel-sand, and sand sub- the upper portion of the anterior wall of the beak cavity. The strates (Howells 2010a). Multiple umbos with intact hinges presence of lateral teeth that are compressed, slightly curved and teeth of L. satura were recovered from archaeological site and not especially long is also diagnostic. Shells of L. satura are 41TR198 on the West Fork of the Upper Trinity. The site, dat- morphologically similar to those of lentic forms of Lampsilis ing between 2400 and 500 years before present, was excavated hydiana (Lea, 1838) (Louisiana fatmucket) and Potamilus pur- in the mid-2000s by GeoMarine, Inc. (now Versar) for which puratus (Lamarck, 1819) (bluefer), two species that occur in the the authors analyzed unionid shell remains (Peter and Harrison Upper Trinity River drainage. Numerous valves of L. hydiana 2011). In this paper we briefl y review previous research on late were present in 41TR198 and all resembled the lotic form of Holocene unionids in the Upper Trinity, describe the L. satura this species, which is characterized as having a thin shell, a remains that were identifi ed, and discuss the conservation rhomboid shell shape, and teeth that are thin and compressed implications of zooarchaeological data for this species. but similar to those seen in other lampsiliid species (see Howells et al. 1996, Howells 2010b for further details). Shells Previous research of P. purpuratus can be confused with those of L. satura due to Applied zooarchaeological research has increased in impor- their moderately thick shell, elevated beaks, and rounded pos- tance during the last two decades (Lyman 2012a, b). Such terior ridge, but L. satura differs from this species in that it research on unionid remains has been important in the has shorter and more compressed lateral teeth, and the dorsal American Southeast, where zooarchaeological data have sup- margin of its shell forms a sigmoid curve. ported natural science or led to revisions of contemporary biogeography (e.g., Parmalee 1956, Gordon 1983, Lyons et al. 2007, Peacock et al. 2011, Peacock 2012, references cited in RESULTS AND DISCUSSION Peacock et al. 2012). In Texas, zooarchaeological data have been important for clarifying the geographic ranges of species An initial analysis of 25 percent of the freshwater mussel in the Trinity River and the Leon River (Randklev et al. 2010a, assemblage from 41TR198 led to the taxonomic identifi cation Randklev and Lundeen 2012, Popejoy et al. 2016,). Species of 2915 shells and shell fragments (Randklev and Wolverton thought to have been rare or absent from these drainages (Neck 2009). Since that time there has been ongoing analysis of the 1982, 1990, Randklev et al. 2013) have been identifi ed in late remaining 75 percent of the sample. Twelve umbo fragments Holocene archaeological faunas. For example, Randklev et al. have been identifi ed as Lampsilis satura. One of these speci-

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