Hafted bifaces known as ‘Big Sandys’ are side-notched lithic tools that are present in Early and Late Archaic contexts, limiting their utility as temporally diagnostic artifacts. I used Cultural Transmission theory to derive an initial expectation that there should be discernable variation due to the incongruous presence of Big Sandys throughout the Archaic and the millennia of time separating the production of these artifacts. I used Geometric Morphometrics to detect potential differences between the haft elements of Early and Late Archaic side-notched points. Statistical analysis of the morphometric data revealed there are differences in the morphology of the haft element between Early and Late Archaic varieties. However, larger sample sizes are necessary to reliably classify a Big Sandy biface from unknown context as belonging to either the Early or Late varieties using morphometrics.

Geometric morphometrics are a useful tool for studying morphological variation in scleractinian corals, extant and extinct. In the case of modern specimens, three-dimensional features of the calical surface can be measured. These features are rarely preserved in fossil corals, however, necessitating measurement of 2-D landmarks in transverse thin-sections of corallites. Unfortunately, 2-D and 3-D methods often yield differing answers to questions about interspecific, intraspecific and intracolonial variation. This issue is addressed in the present study by directly comparing results of 2-D and 3-D geometric morphometric analyses of identical colonies of extant members of the Montastraea "annularis" species complex. Ten colonies of each extant species in the complex (M. annularis s.s., M. faveolata and M. franksi), identified in the field during collection and verified by molecular data, were selected for analysis. Slabs of colony surfaces and transverse thin-sections from ~1 cm below the surface were cut from tops and edges of each colony. Six corallites from each slab were measured in 3-D using a Reflex microscope, and six measured in 2-D on digital images of each transverse thin-section. Both datasets were explored using geometric morphometric methods and analyzed statistically to address questions related to measurement error, intracolonial variation in corallite morphology between tops and edges of colonies, and interspecific morphological differences. The shape data were superimposed using Procrustes generalized least squares, and examined using principal components and canonical variates analyses. Shape differences implied by axes obtained from PCA and CVA were depicted as deformations using the thin-plate spline, to identify which morphological features are correlated with axes of greatest total variance (PCA) and greatest between-group variance (CVA). Goodall's F-test was used to detect significant morphological differences among species and colony positions. All of the data used in these analyses are available in the supplementary file that accompanies this thesis (see Appendix C for a description of the contents of this file). Measurement error analyses show significant differences among variances associated with replicate measurements of 2-D and 3-D landmarks. In many cases the variance is asymmetrical, and for 2D data especially, this asymmetry coincides with orientation of anatomical features. Significant shape differences between corallites from tops and edges of colonies of M. annularis and M. faveolata are found when 3-D data are used. These intracolonial differences are due in large part to height and shape of the septal margin. As a result, 2-D data are unable to find significant differences within colonies. Both datasets find significant interspecific differences, but different anatomical features are found to be responsible. Important interspecific differences for 2-D data are relative thickness of the corallite wall and lengths of septa and costae. When 3-D data are used, results are most influenced by height of primary and secondary septa above the calical surface, as well as length of septa from the corallite wall toward the columella. Patterns of relative morphological similarity among species also differ between datasets. 2-D data show closest similarity between M. annularis and M. faveolata, while M. faveolata and M. franksi are most similar when 3-D data are used. The former result is consistent with previous 2-D analyses, while the latter conclusion is without precedent. Neither is consistent with relationships inferred using molecular data.

The University of Iowa Paleontology Repository maintains an extensive collection of Caribbean coral specimens. This study includes 285 specimens, of which approximately 75 are thin-sections of three previously identified Oligocene genera including: Montastraea Blainville, 1830 (=Orbicella Dana 1846), Antiguastrea Vaughan, 1919, and Agathiphyllia Reuss, 1864 (=Cyathomorpha Reuss, 1868). This study includes: photography of colony surfaces and thin-sections of representative specimens of each species, and the identification of the three Oligocene genera Montastraea, Antiguastrea, and Agathiphyllia to the species level. This study compared the collections with the agathiphyllid stratigraphic ranges in the Paleobiology Database, curated these specimens, and then entered the information into the database, SpecifyTM. These continued efforts aid in better understanding diagnostic morphologic characters of three genera: Antiguastrea, Agathiphyllia, and Montastraea. Two of the genera, Antiguastrea and Agathiphyllia, are extinct. Because the differences in morphology are subtle and not very well understood, previous biodiversity studies using the colony surface for correct species identification have been difficult and often inaccurate. Montastraea is further complicated by recent research that suggests it is polyphyletic and contains multiple species complexes, based on the combined use and creation of more morphological characters and on molecular phylogenetics. Additionally, this study assists with the understanding of the biodiversity of these Oligocene coral genera in the Caribbean region prior to the Plio-Pleistocene extinction event, and the evolutionary history of coral diversity in this region. Though there was an extinction event across the Caribbean, the locality species richness, using Fisher's α and Shannon's H, showed no significant differences between the Late Oligocene formations and the Early Miocene formations.

Eastern newts (Notophthalmus viridescens) are a ubiquitous member of eastern North America’s caudate fauna. Unlike the typical amphibian, their life cycle is split into three phases instead of two, commonly called a triphasic life cycle. The larvae of N. viridescens are fully aquatic, eventually metamorphosing to become terrestrial juveniles called efts. Upon sexual maturity, the eft will metamorphose into a semi-aquatic adult whose external morphology resembles other aquatic salamander species. The eastern newt has predominantly been described by its external traits, namely color changes and lateral tail compression, rather than the musculoskeletal system and anatomy. Since these salamanders occupy different ecological niches (aquatic vs. terrestrial) throughout their lives and likely experience different forces acting on their skeletons, they provide a unique opportunity to study internal changes across ontogeny and ecology. We hypothesize that differences in buoyancy, torsion, and locomotion are expected to result in morphological shape changes across the life stages of the eastern newt’s skeleton. Using image data generated on a SkyScan 1273 micro-computed tomography (µCT) scanner (Bruker), 3D shape analyses will quantify shape differences between individual bones and test the hypothesis. Three-dimensional digital models of each bone of interest will be rendered from the scans in Dragonfly (Object Research Systems). Each 3D model is loaded into SlicerMorph (3DSlicer), where 3D geometric morphometrics is conducted for each bone to test for potential shape differences between each life stage. Our results support a shape difference between eft and adult in particular bones and conserved shape across ontogeny in other bones. Differences in shape are associated with a difference in functional demand across ecological niches.

Dentaries of the 6 species of Myotis that occur in the eastern United States were analyzed using landmark-based geometric morphometrics. The species could be distinguished with a high degree of accuracy. Evidence was found of a phylogenetic signal in the morphology of the Neotropical and Nearctic Myotis sub-clades. There is also evidence of convergence in the morphology of the dentary among Myotis species that feed primarily by gleaning. When analyzed together there was no evidence of sexual dimorphism among the 6 eastern U.S. Myotis, but when analyzed individually some dimorphism may be present. A sample of fossil Myotis of unknown species from Bat Cave, Kentucky, was analyzed in an attempt to identify the specimens to species. Results indicate that Myotis austroriparius and M. sodalis predominate the sample, possibly with smaller numbers of M. grisescens and M. leibii. This study demonstrates the ability to differentiate Myotis taxa from historic and prehistoric sites and provides a tool for researchers to better understand and potentially conserve these species.

Anguispira is a group of common land snails found primarily in eastern North America. There are currently thirteen species recognized within Anguispira. A considerable amount of morphological variation is seen within and among these species, which has lead to much taxonomic confusion within the group. Additionally, because Anguispira species descriptions are based almost exclusively on shell shape and color characteristics, identifying specimens to species is often problematic. In an attempt to delimit species and clarify relationships within Anguispira, regions of the mitochondrial cytochrome oxidase subunit I (cox1), 16S ribosomal RNA (rrnL), and cytochrome b (cob) genes were sequenced from ninety-three individuals representing eleven putative Anguispira species. Variation in shell morphology was also investigated using multivariate analyses of variance. Molecular analyses revealed two currently recognized species (A. alternata and A. cumberlandiana) to be polyphyletic. Evidence also suggested that A. columba, previously synonymized with A. mordax, should be recognized as A. columba and no longer remain synonymized. In addition, several individuals belonging to four strongly supported lineages (which are currently questionable/unidentified) could result in new species.

This thesis focuses on the UK pond newts, the smaller bodied species known as Lissotriton newts and the larger Triturus. The primary aims were to identify and address gaps in the current Tritus/Lissotriton literature; to provide a more complete understanding of this group as many assumptions about morphology and physiology exist untested, for example that larger/fatter females will lay more eggs. Specifically for Lissotriton helveticus, many assumptions are based on the similarly sized Lissotriton vulgaris, potentially missing any species specific differences. A further focus of the work was to provide a clearer view over the whole breeding season; using measures of condition over a season and egg-laying.

Eastern Newts (Notophthalmus viridescens) are a ubiquitous member of eastern North America’s caudate fauna. Unlike the typical amphibian, their life cycle is split into three phases instead of two, commonly called a triphasic life cycle. The larvae of N. viridescens are fully aquatic, eventually metamorphosing to become terrestrial juveniles, called efts. Upon sexual maturity, the eft will metamorphose into a semi-aquatic adult where its external morphology is typical of an aquatic salamander. Since there are apparent differences in their ecological niche, there are different forces acting on their skeletons. We hypothesize that due to differences in buoyancy, torsion, and locomotion, differences are expected in the morphology of the axial skeleton. Using image data generated on a SkyScan 1273 micro-computed tomography (µCT) scanner, 3D shape analyses will be used to quantify shape differences between vertebrae and test the hypothesis. Three dimensional digital models of each vertebrae of interest will be rendered from the scans in Dragonfly (Object Research Systems). Each 3D model is then loaded into SlicerMorph (3D Slicer), where landmarks are placed upon homologous structures on each vertebra. A Generalized Procrustes Analysis (GPA) followed by a Principal Component Analysis (PCA) is conducted for each vertebra to test for potential shape differences between each life stage. GPA and PCA analysis will be conducted on 10 terrestrial juveniles, 10 semi-aquatic adults, 5 aquatic juveniles, and 5 paedomorphic adults. The 5 aquatic juveniles and 5 paedomorphic adults, eastern newts that remain in the water through their entire lives, will validate if the semi-aquatic adult is truly adapting towards an aquatic lifestyle. If GPA and PCA indicate statistical shape differences between certain vertebrae, those vertebrae will be run through the Automated Landmarking through Pointcloud Alignment and Correspondence Analysis (ALPACA) module of SlicerMorph to produce heatmap data on the 3D models showing where exactly the shape changes are occurring in the vertebra.

Tanytrachelos ahynis, a small (21 cm long) aquatic protorosaur from the Upper Triassic sediments in the Cow Branch Formation of the Newark Supergroup, has been briefly described in 1979 by P. E. Olsen. A growing addition of nearly 200 specimens and the availability of CT imaging allow for an extensively detailed redescription. This redescription fills in missing data in cladistic analyses of Protorosauria, allowing for protorosaur monophyly to be retested with a more robust data set. Two hundred and ninety specimens and two CT scans of specimens were examined, with seventy linear measurements, four angular measurements, and five derived variables comprising the quantitative observations. These qualitative and quantitative observations then provided data for Tanytrachelos in two cladistic analyses of Protorosauria. The first analysis included the outgroup Petrolacosaurus, twenty-one protorosaurs, and nine other archosauromorphs. The second analysis included the twenty taxa within this sample that had a data completeness of 50% or higher. Diagnostic qualities of Tanytrachelos include large orbits (11% - 13% the lateral area of the skull), a fused axis and atlas, a tail that spans half the vertebral length, and paired curved heterotopic bones in some specimens (a sign of sexual dimorphism). The disparity of size between the hind and fore limbs, as well as traces of soft tissue, suggest that Tanytrachelos propelled through the water with its back legs. This taxon is similar to Gwyneddosaurus, found in the Lockatong Formation (Newark Supergroup) in Montgomery County, PA, but should maintain its generic name due to lack of diagnostic qualities for Gwyneddosaurus. With the new observations of Tanytrachelos included, each of the two cladistic analyses yielded a single most parsimonious tree presenting a paraphyletic Protorosauria. Both results placed Prolacerta within the confines of Protorosauria, in contrast with the previous suggestion by three publications that Prolacerta was not a true protorosaur. The analysis of all taxa presented Boreopricea as the most basal protorosaur, while the analysis of the twenty most complete taxa presented Protorosaurus as most primitive. Neither tree fully agrees with any previously published data, partly due to differences in taxa sampling between studies. / Ph. D.

Paleontological documentation of hybridization events has the potential to address a multitude of evolutionary and paleobiological issues unanswerable by purely biological means. However, previous studies of modern hybrids suggest that their morphology is often insufficient for their reliable discrimination. This study analyzes the morphology of an extant, genetically-identified <i>Mercenaria</i> spp. (Bivalvia: Veneridae) hybrid zone using Bookstein coordinates and multivariate methods to answer two questions: (1) can hybrid <i>Mercenaria</i> spp. individuals be identified based on morphology alone, and (2) would a <i>Mercenaria</i> spp. hybrid zone be recognizable in the fossil record? Multivariate statistical procedures (principal components analysis, canonical variate analysis, etc.) using Bookstein coordinates demonstrate that, within the hybrid zone, hybrid individuals cannot be identified due to extreme overlap with the parental taxa. The hybrid zone as a whole, however, can be identified by comparison with pure-species populations sampled from outside the hybrid zone. Hybrid zones occupy parental species morphospace plus intermediate morphospace. The technique of using multiple pure-species populations to establish species morphospace is introduced to control for processes that may also result in morphological intermediates at ecological time scales (dimorphism, ecophenotypy, and geographic variation). Four alternative causal explanations of morphological intermediates through geological time (primary intergradation, uncoupled genetic and morphological divergence, time-averaged evolving populations, and developmentally instable populations) are evaluated. A literature survey strongly suggests that neither time-averaging nor developmental instability is occurring at the beginning of a lineage's evolutionary history, and that hybridization may be much more extensive than paleontological data suggest. / Master of Science