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The status of species in freshwater systems shift over time due to natural and anthropogenic causes. Determining the magnitude and cause of these shifts requires a long‐term perspective. This process is complicated when there are also questions about the taxonomic validity of a species. Addressing these issues is important because both can undermine conservation and management efforts if incorrect. Pleurobema riddellii, Louisiana Pigtoe, is under review for protection under the U.S. Endangered Species Act, but its status in the Trinity River basin, where the taxon was described, remains in doubt due to questions about its taxonomy and occurrence within this basin. To address these questions, we compared shell morphometrics of P. riddellii dating to the late Holocene with modern P. riddellii, late Holocene Fusconaia sp., and modern Fusconaia sp. using multivariate analyses to test associations between the putative morphotypes. Based on these analyses, we demonstrate that P. riddellii was likely present in the Trinity during the late Holocene, which indicates questions about its taxonomic validity or presence in this basin are unfounded. Our study further highlights the role zooarchaeological studies can play in status assessments and their utility in better understanding biogeographic patterns for rare species. [ABSTRACT FROM AUTHOR]

Zooarchaeology is the study of animal remains (bone, shell, antler, and other organic tissues) from archaeological sites, which can provide conservation biologists with data on human–environmental interactions with greater time depth than historical records. Such data are of interest because they can be used to study whether or not contemporary animal communities (in this case of freshwater mussels) have changed in terms of species composition or range as a result of human-induced changes to habitat, which is essential for determining a species’ conservation status and formulating actions to protect remaining populations. This study considers whether or not the taxonomic composition of the freshwater mussel community from the Leon River in central Texas differs between the late Holocene and today. Specifically, we analyzed two zooarchaeological assemblages and compared those results with recent surveys conducted within the Leon River. Three species proposed for listing under the Endangered Species Act are found in the zooarchaeological record, of which two are now extirpated from the river basin (Truncilla macrodon and Fusconaia mitchelli). The results of this study provide an example of how zooarchaeological data can be used to evaluate mussel community change through time and provide evidence of range curtailment for threatened mussel species. [ABSTRACT FROM AUTHOR]

Zooarchaeological freshwater mussel remains provide information about past environments, faunal communities, and human behaviors. However, one challenge of using archaeological assemblages of animal remains is differential preservation such that bones and shells of some taxa are more vulnerable to processes that destroy or remove them from the record over time. Thus, remains of some species of freshwater mussels may be underrepresented in terms of presence/absence data as well as abundance compared to the life or death assemblages. Evaluating the representativeness of assemblages before using such data to answer zooarchaeological and paleozoological research questions is common practice in archaeology, particularly for vertebrate remains. However, little research has focused on evaluating representativeness for molluscan assemblages. In this paper, three processes that potentially influence archaeomalacological data are addressed: mussel life history strategies, shell identifiability, and shell robusticity. Expectations about taxonomic abundances in unionid zooarchaeological assemblages are framed and assessed using two datasets from sites from the Leon River in central Texas. As expected, shell robusticity and identifiability influence zooarchaeological abundance data; differences in life history strategy can be used to interpret past stream environments. The expectations derived in this paper can be used as interpretive tools for understanding factors that influence archaeomalacological taxonomic abundance data. [ABSTRACT FROM AUTHOR]

Zooarchaeological data are increasingly important for establishing late Holocene conservation baselines for species of concern. The blue sucker ( Cycleptus elongatus) is experiencing range reduction and is endangered in the State of New Mexico. The early historic (ca. AD 1540) distribution of blue sucker is poorly understood, and the extent of habitat loss is unclear. In 1961, two blue sucker skeletal elements were recovered from a late prehistoric/early historic archaeological site in northern New Mexico called Rainbow House (LA 217). Those remains suggest that the past range of blue sucker was larger; however, since that publication, little consideration has been given to the past presence of this species in the Upper Rio Grande. New zooarchaeological data from a site in northern New Mexico called Ponsipa (LA 297) have revealed the presence of multiple blue sucker skeletal elements. Additionally, a review of site reports and regional archaeological journal publications increased the abundance of blue sucker elements found at Rainbow House and added three archaeological sites where blue sucker has been reported in the region. Collectively, this information suggests a broader pre-impoundment distribution for blue sucker than previously recognized and can help establish a new baseline for their conservation or restoration in New Mexico. [ABSTRACT FROM AUTHOR]

Previous research on intensification in hunter gatherer strategies from Central West Argentina ca. 2000 years BP states that human demographic packing and overhunting of guanacos ( Lama guanicoe ) may have caused resource depression of this large prey animal. As a result, people broadened their diet to include smaller prey animals. Evidence supporting this conclusion includes an increase in Shannon's Diversity Index and a decrease in the abundance of artiodactyl remains over time in southern Mendoza. However, these studies about change in diet breadth did not consider the importance of spatial scale on analysis of prey choice and diet breadth and used the entire region as a unit of analysis. This is problematic because southern Mendoza has a heterogeneous landscape. In this paper we analyze different faunal abundance indices considering different spatial scales and the representativeness of the zooarchaeological samples. The results of the analyses show distinctive patterns of resource use over time at the macro- and subregional scales. Some of the difference can be explained by environmental differences between subregions and others might relate to differences in sample representativeness between subregions. [ABSTRACT FROM AUTHOR]

Abstract: Expectations for survival of vertebrate remains have been well developed and intensely studied in the zooarchaeological taphonomic literature. Taphonomic studies of shellfish remains focus on marine species and on variables relevant to remains from paleontological contexts (e.g., fossil marine beds). In this paper we develop a conceptual framework from which to derive expectations concerning the preservation of freshwater mussel remains focusing on two parameters, shell microstructure and shell shape. Shell size does not influence survivorship. Our model is validated through application to late Holocene zooarchaeological mussel assemblages from north Texas. Taphonomically robust species are important regarding zooarchaeological and biogeographic interpretations based on mussel paleofaunas, and fragile species are important indicators of whether or not an assemblage is well preserved. [Copyright &y& Elsevier]

Abstract: Biometry is useful for a suite of analyses relevant to zooarchaeology, which include analysis of mortality profiles, taphonomy, paleoecology, among other purposes. Here, size-age prediction models are developed for 10 freshwater mussel species found in north Texas to develop a method for studying paleoenvironmental conditions. Shell length is often used to evaluate the structures of modern mussel populations, but its use on paleozoological specimens is not feasible because complete shells rarely preserve. Instead, pallial line-to-lateral teeth length (PLL) and pseudocardinal teeth-to-pallial line length (PSP) are evaluated as proxy measures for shell length. Linear regression models based on PLL and PSP using modern mussels demonstrate that they are accurate proxies of shell length for multiple species from a variety of habitats. In addition, ontogenetic-age structures for a modern sample and for two late Holocene assemblages from north Texas are developed using PLL and PSP. These techniques are useful tools for evaluating past ecological conditions of freshwater mussel populations when large samples are available for study, which expands analytical potential of zooarchaeological studies of prehistoric unionid remains. [Copyright &y& Elsevier]

Remains of 22 American black bears (Ursus americanus) were excavated from 2 natural trap caves in Missouri during the late 1950s. Age, sex, and size characteristics based on analysis of ursid teeth from the caves corroborates wildlife studies that suggest that subadult to young-adult male bears are relatively vulnerable to accidental deaths in their search for food compared to members of other age-sex cohorts. This information is of interest to wildlife biologists given that North American bears and humans increasingly share habitat. Data on native Missouri black bears are also of general interest because little is known about this population, which was extirpated by the beginning of the twentieth century, and because a reintroduced population is expanding in the southern portion of the state. [ABSTRACT FROM AUTHOR]

Archaeological studies of temporal changes in human predation strategy using foraging theory tend to focus on the role of overexploitation of important prey resources and resulting resource depression. An alternative use of the prey- choice model framed under foraging theory is to investigate the influence of environmental changes, such as increases in climate stress, on prey availability. Environmental change can be expected to produce many of the same effects on human predation strategy as resource depression. Here analytical techniques typically used to study the effects of over-predation and resource depression caused by humans are used to monitor their response to fluctuations in prey availability related to climate change during the Holocene in Missouri. Data and interpretations presented here add to the growing body of zooarchaeological foraging theory literature implicating environmental change as a critical factor in human diet. [ABSTRACT FROM AUTHOR]