No description available.

This thesis concentrates on discovering the best consolidant or consolidants for stabilizing a Columbian mammoth’s sub-fossilized mandibles, a distal femur, an ulna, a radius, and a tooth. It was recovered from a wet, sandy gravel pit owned by the Vernor Family located in Clute, Texas. Based on thermoluminescence dating, the mammoth dates to around 66,000 years ago. The bones are fragile and unstable. They retain a minute amount of organic material (collagen) and hydroxyapatite, but not enough to retain any structural support. Experiments and analyses were conducted on various bone samples to compare each of the following consolidants’ properties. The consolidants examined were silicone oil, polyvinyl acetate (PVA) with viscosity of 25, Acryloid B-72, Butvar 98, Starbond EM-02, methyltrimethoxysilane (MTMS), Paleo-bond, and Rhoplex (Primal) WS24. Stability, strength, and appearance were evaluated by measurable observations. The Scanning Electron Microscope (SEM) and the Environmental Scanning Electron Microscope (ESEM) at the Microscopy and Imaging Center at Texas A&M University were used to map penetration of these consolidants. SEM was utilized for both imaging and energy-dispersive x-ray spectroscopy (EDS) to examine the presence and absence of certain elements. ESEM was used to view consolidants at the microscopic level to further examine the bonding between the consolidant and the bone’s cellular structure. By examining and testing all the consolidants, methyltrimethoxysilane (MTMS) was chosen to stabilize the ulna, radius, left and right mandibles, distal femur, and tooth. This research opened new avenues to different methods in preserving sub-fossilized bone and broadens our understanding of bone conservation.

This thesis concentrates on discovering the best consolidant or consolidants for stabilizing a Columbian mammoth’s sub-fossilized mandibles, a distal femur, an ulna, a radius, and a tooth. It was recovered from a wet, sandy gravel pit owned by the Vernor Family located in Clute, Texas. Based on thermoluminescence dating, the mammoth dates to around 66,000 years ago. The bones are fragile and unstable. They retain a minute amount of organic material (collagen) and hydroxyapatite, but not enough to retain any structural support. Experiments and analyses were conducted on various bone samples to compare each of the following consolidants’ properties. The consolidants examined were silicone oil, polyvinyl acetate (PVA) with viscosity of 25, Acryloid B-72, Butvar 98, Starbond EM-02, methyltrimethoxysilane (MTMS), Paleo-bond, and Rhoplex (Primal) WS24. Stability, strength, and appearance were evaluated by measurable observations. The Scanning Electron Microscope (SEM) and the Environmental Scanning Electron Microscope (ESEM) at the Microscopy and Imaging Center at Texas A&M University were used to map penetration of these consolidants. SEM was utilized for both imaging and energy-dispersive x-ray spectroscopy (EDS) to examine the presence and absence of certain elements. ESEM was used to view consolidants at the microscopic level to further examine the bonding between the consolidant and the bone’s cellular structure. By examining and testing all the consolidants, methyltrimethoxysilane (MTMS) was chosen to stabilize the ulna, radius, left and right mandibles, distal femur, and tooth. This research opened new avenues to different methods in preserving sub-fossilized bone and broadens our understanding of bone conservation.

No description available.

A long-term forest monitoring program was initiated at Mammoth Cave National Park (MCNP). The objectives of this project were to establish baseline data on the representative forest community types at MCNP based on dominant tree species. Permanent monitoring plots were established in different forest community types throughout the park. A total of 32 permanent plots were established for a combined sample area of 11.4 hectares. All stems larger than 5 cm dbh were measured and mapped within each permanent plot. Data on saplings were also collected. Distributions and abundances were determined for all species in permanent plots and combined for community type summaries. Stand tables were generated for four stem diameter size categories for each permanent plot. Stand analyses included calculation of values for species in four size categories.The results describe the forests of MCNP in various stages of succession. There is a trend toward increasing dominance of shade tolerant species in several of the community types. Species composition is in transition from the dry site, shade intolerant species in the canopy to shade tolerant species in the understory. Corpus f lorida, Acer saccharum, Fagus grandifolia, and Acer rubrum are prominent species in the understory and sapling layers. Early successional species continue to dominate heavily or recently disturbed locations on karst and dry upland sites. Juniperus virginiana is the dominant species in three of the seven community types sampled. The Hemlock and Beech-Maple Communities, Community Types II and VIII, appear to be maintaining their present species compositions and community structures. These are successionally "mature" forests, and include some of the most ecologically important areas of the park. However, Betula alleghaniensis is not reproducing in the Hemlock ravines community type, the only sites where this species occurs. Ailanthus altissima, an invasive exotic tree, was found in several of the areas sampled. / Department of Biology

Remains of a mammoth, other Pleistocene fauna, and a wooden bowl were recovered from the Vernor site located in Clute, Brazoria County on the Texas Gulf Coast. Stratigraphy, sedimentology, and geochronology were used to establish the depositional history of the site. The geologic evidence suggests that these sediments were deposited during a period of fluvial activity by an ancient meander belt of the Brazos River, known today as Oyster Creek, which characterized this region during the Late Pleistocene and Early Holocene. Organics associated with the wooden bowl were radiocarbon dated to 4205 + 30 yr B.P. (UCIAMS-12039), while sand grains associated with the remains of the mammoth were dated using the luminescence technique to 66,000 + 7000 yr B.P. (UIC1383). According to these dates and their positions in the stratigraphic record, it was established that the mammoth and other Pleistocene age fauna preceded human occupation, and are not contemporaneous with the wooden bowl.

No description available.

One of the most challenging questions surrounding the Clovis colonization of North America is the character and structure of terminal Pleistocene environments, including floral and faunal communities. A series of cores in the mouth of an arroyo revealed late Pleistocene - early Holocene wetland sediments buried 12 meters below surface, at the approximate elevation of the entrenched modern San Pedro River channel. A suite of ¹⁴C dates show that wetlands of the ancestral San Pedro River occupied portions of the inner valley coincident with the Younger Dryas (13,000 - 11,500 cal yr BP) and the early Holocene (10,000 - 9,500 cal yr BP). A lack of Sporormiella fungal spores indicates that mammoths were rare or absent when Clovis populations appeared in the valley around 12,800 cal yr BP. Palynological and stable carbon isotope analyses show that C₄ grasses increased at 9,940 cal yr BP, just prior to frequent burning after 9,510 cal yr BP and rapid erosion at 9,470 cal yr BP. δ ¹⁸O values from soil carbonates vary but do not record a systematic shift in precipitation source or temperature during the late Pleistocene - early Holocene transition. The establishment of C₄ grasslands in the inner valley correlates with widespread changes in the Chihuahuan Desert flora around 10,000 cal yr BP. A relatively dense accumulation of Clovis-mammoth associations in San Pedro Basin contrasts the lack of megaherbivores indicated at Palominas Arroyo. The upper San Pedro Basin of southeastern Arizona contains a minimum of four Clovis-mammoth associations, making it possibly one of the densest concentrations of human-proboscidean sites on earth in terms of time and space. I use the Younger Dryas-age stratum known as the "black mat" to compare the Clovis-age archaeofaunal record of the basin to its paleontological background in order to measure the level of human predation that created this remarkable record. This analysis indicates that Clovis people were affecting the last mammoth populations to a significant degree, a situation expected only in the presence of abundant mammoths. I argue that this condition was met in the San Pedro Basin, possibly in the form of a terminal Pleistocene refugium. If the refuge hypothesis indeed explains mammoth predation, then Clovis-mammoth associations should occur as clusters as they do in the San Pedro Basin rather than as isolates as they are known to occur elsewhere. The use of radiocarbon frequency distributions to reconstruct prehistoric human and animal populations must account for taphonomic loss and other factors that affect the archaeological and paleontological records. Surovell et al. (Journal of Archaeological Sciences, 36, 1715–1724) have recently proposed a volcanic-based correction factor for removing "taphonomic bias" from temporal frequency distributions. Analysis of 718 radiocarbon dates sampled from the alluvium of the San Pedro and Santa Cruz Rivers and their tributaries in southeastern Arizona shows that discovery and scientific biases play an equally important role in the creation of radiocarbon frequency distributions, and that "taphonomic bias" has not been systematic through time. The latter principle is further demonstrated using a sample of 123 Pliocene to Clovis-age proboscideans from the San Pedro Valley. We propose an alternative model that is based on the nature of the stratigraphic record, with discovery bias, scientific bias, taphonomic loss, and the shape of the calibration curve all operating to influence the temporal frequency distribution of prehistoric phenomena.

AN ISOTOPIC EXAMINATION OF CAVE, SPRING AND EPIGEAN TROPHIC STRUCTURES IN MAMMOTH CAVE NATIONAL PARK Name: Zacchaeus Greg Compson Date: October 15, 2004 Pages: 56 Directed by: Philip Lienesch, Doug McElroy, Michael Stokes and Richard Bowker Department of Biology Western Kentucky University Abstract High-water events in the Green River result in flow-reversals which flush native and introduced fishes into Mammoth Cave, posing threats to indigenous cave fauna. However, little is known about the trophic interactions between cave and epigean aquatic systems or their connectivity via natural springs. The purpose of this study was to use stable isotopes of C and N to describe and compare the trophic structure of epigean, spring and cave aquatic systems within Mammoth Cave National Park. Fourteen sites were sampled from fall 2002 to fall 2003; four in the Green River (epigean), four in spring-heads, and three inside Mammoth Cave. Two a priori hypotheses were tested: fish and invertebrates living in spring heads should express delta 13C values intermediate to those of organisms in cave and epigean aquatic systems and overall trophic levels in cave and spring samples should be compressed, showing lower delta15N values compared to epigean sites. Though cave and spring systems were dominated by allochthonous leaf litter, characteristic of headwater streams, the epigean system was also largely dependent on detrital inputs. Primary differences in delta13C were seen at higher trophic levels, particularly in top consumers such as Lepomis species, where delta13C values decreased from epigean to spring to cave habitats. Though all three habitats supported a similar number of trophic levels (N: 5), the trophic structure was compressed in cave and spring compared to epigean habitats. This trend, however, was obfuscated by delta15N values of accidental species in caves, which tended to be enriched, even when compared to epigean signals. This was attributed to either trophic enrichment from yolk sacs or starvation and subsequent self-processing. Overall, spring trophic structure was found to be intermediate to cave and epigean trophic structures in terms of delta13C values of upper-level fish consumers, but spring trophic structure was more similar to the cave trophic structure in terms of delta15N values, excluding cave accidentals.

A monitoring program of forest herbs was initiated at Mammoth Cave National Park (MCNP). The objectives of this project were to produce a quantitative description of the current forest herb communities which can be used as a baseline for monitoring future change as well as a foundation for making informed management decisions. Herbaceous vegetation in previously established permanent forest monitoring plots was characterized during the summers of 1993-94. In the future, these baseline data can be used to detect changes in forest herb communities that might result from natural succession, management decisions and/or environmental changes. The landuse history for these plots was evaluated as a factor affecting the present diversity, richness and cover of the forest herbs at Mammoth Cave National Park. Prior to the establishment of MCNP, landuse consisted of a mosaic of agriculture, logging, and grazing. The park provides unique natural experiment to study the recovery of vegetation following a variety of human influenced disturbances.Thirty-two permanent plots were used to collect species presence and cover in early spring and mid-summer. Five forest herb communities were classified for spring and summer. All plots for the spring and summer community classification were the same except for two. Environmental variables, overstory vegetation, and previous landuse are identified as variables that have significant associations with herbaceous composition. Herbaceous cover, richness, and diversity were higher in areas that were forested before park establishment. The results of this study support the contention that human induced disturbances have more detrimental effect on forest herbs compared to overstory tree species. / Department of Biology