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Exploring The Relationships Between Mammalian Functional Trait Distributions And Regional Biomes, With Application To Miocene Paleoecology, Devra Hock-Reid

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Paleoecology relies on understanding relationships between modern animals and their environment. Animals are adapted to niches in their environments, and those physical adaptations, or functional traits, are utilized as proxies to interpret aspects of paleo-ecosystems. Much is known about individual functional traits in extant mammals and their relationship to the environment. Less is known about how multiple functional traits across a community can be utilized for paleoecological interpretations. I develop models utilizing traits in mammalian communities at the biome level. For Chapter 1, I build a model for North American regional biomes using mammalian trait frequencies. I quantify changes in …

Male Mastodon Landscape Use Changed With Maturation (Late Pleistocene, North America), Joshua H. Miller, Daniel C. Fisher, Brooke E. Crowley, Ross Secord, Bledar A. Konomi

Department of Earth and Atmospheric Sciences: Faculty Publications

Under harsh Pleistocene climates, migration and other forms of seasonally patterned landscape use were likely critical for reproductive success of mastodons (Mammut americanum) and other megafauna. However, little is known about how their geographic ranges and mobility fluctuated seasonally or changed with sexual maturity. We used a spatially explicit movement model that coupled strontium and oxygen isotopes from two serially sampled intervals (5+ adolescent years and 3+ adult years) in a male mastodon tusk to test for changes in landscape use associated with maturation and reproductive phenology. The mastodon’s early adolescent home range was geographically restricted, with no evidence of …

Changes In Mammalian Abundance Through The Eocene-Oligocene Climate Transition In The White River Group Of Nebraska, Usa, Robert Gillham

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Marine records show major cooling during the Eocene-Oligocene Climate Transition (EOCT). Most proxy studies in the White River Group suggest drying across the EOCT, and some suggest cooling. The lower resolution continental record has hindered a direct correlation of the marine climate record to Nebraska. I explore various correlation schemes and what they imply for faunal changes. This study compiles and analyzes data from 4,875 specimens in the University of Nebraska State Museum (UNSM) collection to test the hypothesis that climate change across the Eocene-Oligocene (E-O) boundary caused significant abundance changes in mammals. A series of binning schemes was created. …

A Taxon-Free, Multi-Proxy Model For Making Paleoecological Interpretations Of Neogene North American Faunas, Devra G. Hock

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Proxies used for interpreting the paleoecology of extinct vertebrate communities are usually based on modern ecosystems, with many developed from Old World ecosystems. However, because no model is completely taxon-free and phylogenetic influences cannot be entirely discounted, these proxies may not be appropriate for paleoecological interpretations of North American ecosystems. Additionally, many proxies based on modern vertebrate communities exclude small-bodied mammals. Here I explore several new paleoecological models based on the frequency of mammalian traits within three ecological categories: locomotion, diet, and body mass. Since these models are intended for interpreting paleoenvironments occupied by Neogene North American mammals, the data …

The Carnivores Of Agate Fossil Beds National Monument: Miocene Dens And Waterhole In The Valley Of A Dryland Paleoriver, Robert M. Hunt Jr., Robert Skolnick, Joshua Kaufman

Zea E-Books Collection

In 1981 University of Nebraska paleontologists came upon an unexpected concentration of carnivore dens at Agate Fossil Beds National Monument in northwest Nebraska. The discovery of bones of Miocene beardogs, mustelids, and canids in their burrows was unparalleled and marked an exceptional event in the fossil record. Survey and excavation (1981–1990) established that six species of carnivores had, over time, occupied the dens with traces of their prey: juvenile and adult oreodonts, camels, and a neonatal rhinoceros. At least nine individuals of the wolf-like beardog Daphoenodon superbus, the most common carnivore, were identified from remains of young, mature, and aged …

Middle Miocene Paleoenvironmental Reconstruction Of The Central Great Plains From Stable Carbon Isotopes In Large Mammals, Willow H. Nguy

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Middle Miocene (18-12 Mya) mammalian faunas of the North American Great Plains contained a much higher diversity of apparent browsers than any modern biome. This has been attributed to greater primary productivity, which may have supported greater browser diversity that commonly corresponds with densely vegetated habitats. However, several lines of proxy evidence suggest that open woodlands or savannas dominated middle Miocene biomes; neither of which support many browsers today. Stable carbon isotopes in mammalian herbivore tooth enamel were used to reconstruct vegetation structure of middle Miocene biomes.

Stable carbon isotopes in C₃ dominated environments reflect vegetation density and herbivores …

Reconstructing The Paleoecology And Biogeography Of Rhinoceroses (Mammalia: Rhinocerotidae) In The Great Plains Of North America, Leading Up To Their Extinction In The Early Pliocene, Bian Wang

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Members of the family Rhinocerotidae first appeared in the middle Eocene and were one of most successful mammal groups of the Oligocene and Miocene in North America. Their extinction in the early Pliocene has been attributed to several causes, including cooling climate, an expansion of C₄ grasslands, and faunal turnover favoring high-crowned, open habitat-adapted mammalian taxa. This study tests whether the extinction of North American rhinoceroses in the Great Plains was abrupt or gradual by examining changes in their paleogeographic distribution in a series of time-slices through the Barstovian, Clarendonian, and Hemphillian North American land-mammal ages. It further examines …

Constraining Neogene Temperature And Precipitation Histories In The Central Great Plains Using The Fossil Record Of Alligator, Evan Whiting

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Most amphibians and reptiles (excluding birds) are poikilothermic; their internal body temperature varies with that of their external environment. This makes them useful as climate proxies, especially when linked to geographic distributions of ambient climate. I evaluate the utility of the extant crocodylian genus Alligator as a paleoclimate proxy for the Central Great Plains (CGP) using species distribution modeling. Alligator is a readily identifiable taxon with a good CGP fossil record during the Neogene (~23–2.6 Ma). Alligator first appeared in the CGP in the late Eocene (~37 Ma), was absent during most of the Oligocene, reappeared in the early Miocene …

Ecology And Morphology Of The Late Miocene Musk Deer, Longirostromeryx Wellsi (Artiodactyla: Moschidae: Blastomerycinae), Katheryn Y. C. Chen

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Longirostromeryx wellsi, one of the latest surviving members of the extinct clade Blastomerycinae (Artiodactyla: Moschidae), possesses highly derived craniodental morphology that deviates from typical musk deer form. Previous work suggests that the unique anatomy of L. wellsi represents adaptations for occupying open savannas. To test this hypothesis I conduct principal components analysis on five postcranial bones of L. wellsi, comparing them to that of several extant ruminant artiodactyls, which are divided among seven habitat categories. These elements are also compared with the postcrania of other blastomerycines. These analyses indicate that L. wellsi anatomy is most similar to that of other …

Climate Effects On Mammalian Body Size And Grassland Composition Inferred From Late Quaternary Grazers In The Great Plains Of North America, Tom Baldvins

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Several mammalian taxa exhibited a diminution during the Pleistocene-Holocene transition. Two hypotheses have been proposed to explain this phenomenon: (1) human hunting and (2) climate change along with its effects on grasslands. I use stable isotopes from a variety of Quaternary grazing mammals to measure grassland changes following the Last Glacial Maximum (LGM) in Nebraska and to develop a climate proxy to compare with mammalian body size. Results indicate that latest Pleistocene equids and mammoths have δ¹³C values indicative of a C₃ or mixed C₃/C₄ diet. However, Holocene bison have greatly elevated δ^{13 …}

Body Size And Species Richness Changes In Glyptosaurinae (Squamata: Anguidae) Through Climatic Transitions Of The North American Cenozoic, Sara Elshafie

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Poikilothermic vertebrates offer excellent climate proxies based on relationships between environment and measurable variables such as body size and species richness. Relationships of these variables in lizards to environmental transitions over long time scales are poorly understood. Here I show that patterns of body size and species richness in a lizard clade, Glyptosaurinae (Squamata: Anguidae), correspond to known histories of paleotemperatures through the Cenozoic of North America. Glyptosaurines have the richest fossil record among North American Cenozoic lizards and exhibit a wide range of skull sizes. In order to estimate body size for glyptosaurines and other fossil anguids, I collected …

Patterns Of Maximum Body Size Evolution In Cenozoic Land Mammals: Eco-Evolutionary Processes And Abiotic Forcing, Juha J. Saarinen, Alison G. Boyer, James H. Brown, Daniel P. Costa, S.K. Morgan Ernest, Alistair R. Evans, Mikael Fortelius, John L. Gittleman, Marcus J. Hamilton, Larisa E, Harding, Kari Lintulaakso, S. Kathleen Lyons, Jordan G. Okie, Richard M. Sibly, Patrick R. Stephens, Jessica Theodor, Mark D. Uhen, Felisa A. Smith

School of Biological Sciences: Faculty Publications

There is accumulating evidence that macroevolutionary patterns of mammal evolution during the Cenozoic follow similar trajectories on different continents. This would suggest that such patterns are strongly determined by global abiotic factors, such as climate, or by basic eco-evolutionary processes such as filling of niches by specialization. The similarity of pattern would be expected to extend to the history of individual clades. Here, we investigate the temporal distribution of maximum size observed within individual orders globally and on separate continents. While the maximum size of individual orders of large land mammals show differences and comprise several families, the times at …

Paleoecology Of Nebraska’S Ungulates During The Eocene-Oligocene Climate Transition, Grant S. Boardman

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The White River Group (WRG) preserves the Eocene-Oligocene climate transition (EOCT), an interval of global cooling and drying during the onset of Antarctic glaciation. In the Great Plains, a shift from forested conditions to drier woodland-savanna biomes is hypothesized to have occurred at this time. I test this hypothesis through the analyses of several paleoenvironmental proxies on the teeth of 12 WRG ungulate species: stable carbon and oxygen isotopes from tooth enamel, and mesowear and microwear texture. The EOCT shift toward more open habitats and lower vegetation density under drying climates should have resulted in an increase in mean carbon …

New Stable Isotope Record Of Paleoecological Change In The Late Neogene Of The Western Great Plains From Enamel In Large Mammals, Zachary Kita

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

An expansion of C₄ grasslands occurred between 6 and 8 million years ago in the Great Plains of North America, as evidenced by a marked shift to more ¹³C-enriched carbon isotope compositions from large fossil mammal tooth enamel and paleosol carbonates. Prior to this expansion, habitats were comprised of exclusively C₃ vegetation. To explore this problem I present a compilation of bulk stable carbon (δ¹³C) and oxygen (δ¹⁸O) isotope values from a variety of large mammals from 6 localities that span from the late Clarendonian to the late Blancan in Nebraska. As expected, …

An Analysis Of Anchitherine Equids Across The Eocene–Oligocene Boundary In The White River Group Of The Western Great Plains, David M. Masciale

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Anchitherine horses are a subfamily of equids that are abundantly represented in the late Eocene and early Oligocene of North America. This group has been heavily studied in the past, but important questions still remain. Some studies have focused on the Eocene-Oligocene boundary and have used these equids along with other taxa to study mammalian diet and climate change through this interval. I reexamine two anchitherine genera, Mesohippus and Miohippus, from stratigraphic sequences of the White River Group in western Nebraska and southwestern South Dakota. These sequences span the Chadronian (late Eocene), Orellan (early Oligocene), and Whitneyan (early Oligocene) …

Body Mass Of Late Quaternary Mammals (Data Set), Felisa A. Smith, S. Kathleen Lyons, S.K. Morgan Ernest, Kate E. Jones, Kansas State University, Tamar Dayan, Pablo A. Marquet, James H. Brown, John P. Haskell

School of Biological Sciences: Faculty Publications

The purpose of this data set was to compile body mass information for all mammals on Earth so that we could investigate the patterns of body mass seen across geographic and taxonomic space and evolutionary time. We were interested in the heritability of body size across taxonomic groups (How conserved is body mass within a genus, family, and order?), in the overall pattern of body mass across continents (Do the moments and other descriptive statistics remain the same across geographic space?), and over evolutionary time (How quickly did body mass patterns iterate on the patterns seen today? Were the Pleistocene …

Amphicyonidae, Robert Hunt

University of Nebraska State Museum: Mammalogy Papers

The Amphicyonidae occur in North America from late Eocene (~40 Ma) to early late Miocene (~9 Ma), a span of 31 million years. In the North American land mammal biochronology, this diverse family extends from the Duchesnean to the end of the Clarendonian and is especially well represented in the Miocene (~5-24 Ma). In the Old World, amphicyonids survive no longer than in North America: The last European records are Vallesian (Dinotheriensande, Mainz Basin, Germany, Kuss, 1965, Tobien, 1980; Vallés-Penédes Basin, Spain, Crusafont-Pairó and Kurten, 1976), and the last representative may occur at about 9 Ma at Kohfidisch, Austria (latest …

Geologic History Of Ash Hollow State Historical Park, Nebraska, Robert F. Diffendal Jr., Roger K. Pabian, J. R. Thomasson

Conservation and Survey Division

Contents:

Introduction
Acknowledgments
Cautions
General Stratigraphy
Oligocene Series-White River Group-Brule Formation-Whitney Member
Miocene Series-Ogallala Group-Ash Hollow Formation
Pliocene Series-Broadwater Formation
Quaternary deposits
Older colluvium and loess
Younger colluvium and alluvium
General Paleontology
Evidence of past life: fossils and subfossils
Collecting fossils
Vertebrate fossils
Fossils from the Whitney Member of the Brule Formation
Plants
Invertebrates
Vertebrates
Fossils from the Ash Hollow Formation
Plants
Invertebrates
Vertebrates
Fossils from the Broadwater Formation
Plants
Vertebrates
Quaternary fossils
Plants
Invertebrates
Vertebrates
Additional studies of Nebraska fossils
Geologic History
Prehistory and History
References
Appendices I-IV

Cenozoic Mammals From The Central Great Plains, C. Bertrand Schultz, Larry D. Martin, R. George Corner, Lloyd G. Tanner

Bulletin of the University of Nebraska State Museum

Includes:

Part 1. Middle and Late Cenozoic Tapirs from Nebraska. By C. Bertrand Schultz, Larry D. Martin, and R. George Corner.

Part 2. Stratigraphic Occurrences of Teleoceras, with a New Kimballian Species from Nebraska. By Lloyd G. Tanner.

Part 3. A New Kimballian Peccary from Nebraska. By C. Bertrand Schultz and Larry D. Martin.

Part 4. Bears (Ursidae) from the Late Cenozoic of Nebraska. By C. Bertrand Schultz and Larry D. Martin.

Part 5. Scimitar-toothed Cats, Machairodus and Nimravides, from the Pliocene of Kansas and Nebraska. By Larry D. Martin and C. Bertrand Schultz.

84 pp

A New Kimballian Peccary From Nebraska, C. Bertrand Schultz, Larry D. Martin

Bulletin of the University of Nebraska State Museum

A new species of Pliocene peccary, Prosthennops (Macrogens) graffhami; is described from the Kimball Formation, Ogallala Group, Frontier County, Nebraska. This new species is the latest in geologic age and most advanced in the genus.

The remains of fossil vertebrates are generally rare in the upper part of the Ogallala group, and some have maintained that Hemphillian faunas such as Coffee Ranch and Smith County, Kansas, represent the latest Ogallala faunas. Later faunas than are typically considered as Hemphillian, containing more advanced forms, occur in the Kimball Formation and deposits of equivalent age. Known faunas which may …

Bears (Ursidae) From The Late Cenozoic Of Nebraska, C. Bertrand Schultz, Larry D. Martin

Bulletin of the University of Nebraska State Museum

A ramus and partial premaxilla establish the presence of a new subspecies of Indarctos in the upper Pliocene (Kimball Formation, Ogallala Group) of Frontier County, Nebraska. An extremely large species of Agriotherium is represented by fragmentary remains from the middle Pliocene (middle part of Ash Hollow Formation, Ogallala Group) of Sherman County, Nebraska.

This study is part of a series of papers dealing primarily with the fauna of the Kimball formation in Nebraska (Barbour 1927, 1929; Barbour and Schultz, 1941; Schultz and Stout, 1948, 1961; Kent 1963, 1967; Tanner, 1967; Short, 1969; Martin and Tate, 1970; Schultz, Schultz, and Martin, …

Stratigraphic Occurrences Of Teleoceras With A New Kimballianspecies From Nebraska, Lloyd G. Tanner

Bulletin of the University of Nebraska State Museum

Study of Teleoceras remains in the University of Nebraska State Museum indicates that this specialized, short-limbed rhinoceros inhabited the Central Great Plains from Early through Late Pliocene. Previously thought to have become extinct at the end of the middle Pliocene, this genus is now known from the very latest Pliocene. A new species, Teleoceras schultzi, is described from the Kimball Formation, Ogallala Group, Frontier County, Nebraska.

A New Species Of Menoceras From The Marsland Formation Of Nebraska, Lloyd G. Tanner

Bulletin of the University of Nebraska State Museum

Further study indicates that the Menoceras remains collected from the "Bridgeport Quarries" (lower port:on or the Marsland Formation, Middle Miocene, of the Hemingford Group) are of a new species.

In 1962, these dicerathere remains were considered to be a geologic variety of Diceratherium niobrarensis (Stecher, Schultz, and Tanner). However, later (Tanner, 1969) a generic distinction was revived, separating the Menoceras Troxell from Diceratherium Marsh. Diceretherium niobrarensis was then placed in synonymy with Menoceras arikarense (Barbour).

The new species is an intermediate between Menoceras arikarense (Barbour) from the Harrison Formation and Menoceras marslandensis Tanner, from the upper portion of the Marsland …

Two Lynx-Like Cats From The Pliocene And Pleistocene, C. Bertrand Schultz, Larry D. Martin

Bulletin of the University of Nebraska State Museum

A new species (Lynx stouti) of small felid is described from the lower Pliocene of Colorado. This form has several characters in common with the modern Lynx and may be ancestral to that genus. A new subspecies of Lynx issiodorensis Croizet and Jobert is described as L. i. kurteni from the Mullen Assemblage, Cherry County, Nebraska. The relationships of this form to other lynxes are discussed along with the paleo-distribution of the genus.

The classification of the felinae has always been somewhat controversial, especially at the generic level. One fairly homogenous group of cats which has been separated …

Phyletic Trends In Certain Lineages Of Quaternary Mammals, C. Bertrand Schultz, Lloyd G. Tanner, Lary D. Martin

Bulletin of the University of Nebraska State Museum

Evolutionary trends in certain carnivores, rodents, bovids, and proboscideans are examined. Chronoclines are demonstrated for muskrats, beavers, mammoths, and bison. The Pliocene-Pleistocene boundary and Quaternary climatic fluctuations are also discussed.

The University of Nebraska State Museum contains a large stratigraphically controlled collection of Pleistocene animals. This collection provides a unique opportunity for the study of phyletic trends in certain lineages of mammals. Although a few phylogenetic lineages have been proposed (Schultz and Frankforter, 1946; Hibbard, et al., 1965), this has not been done for the vast majority of Pleistocene mammals. However, there is much more data available than this would …

The Microtine Rodents Of The Mullen Assemblage From The Pleistocene Of North Central Nebraska, Larry D. Martin

Bulletin of the University of Nebraska State Museum

The University of Nebraska State Museum has had an active collecting program in Hooker and Cherry counties, Nebraska, since the 1930's. The following University of Nebraska State Museum collecting localities have been extensively excavated: Cr-10, Cr-102, Cr-11, Ho-101, Ho-102, and Ho-103. These localities have produced a large vertebrate fauna described by Jakway as the Mullen Local Fauna which he considered for the most part to be Early lllinoian. Further study of this local fauna now demonstrates that assemblage does include Early as well as Middle Pleistocene animals. The purpose of this paper is to report on the evidence regarding the …

A New Rhinoceros From The Nebraska Miocene, Lloyd G. Tanner

Bulletin of the University of Nebraska State Museum

A new species of rhinoceros, Menoceras marslandensis, is here proposed. It is based upon a nearly complete skull from the upper part of the Marsland Formation, Hemingford Group (Miocene), of Box Butte County, Nebraska. The new species was probably derived from Menoceras arikarense (Barbour), collected from the Agate Springs Quarries (Arikaree Group, Harrison Formation) of Sioux County, Nebraska, with which both Diceratherium niobrarensis Peterson and D. cooki Peterson are likely synonymous. From Menoceras arikarense, the presumed ancestral stock, Menoceras marslandensis differs in possessing the following characters: (1) very long, fused but slightly cleft, nasals, with flattened, rugose areas …

Precambrian Well Data In Nebraska, Including Rock Type And Surface Configuration, Marvin P. Carlson

Conservation and Survey Division

This bulletin presents, in tabular form, information relating to the Precambrian surface and includes a configuration map of this surface in Nebraska. The data from all of the 1460 deep tests reaching the Precambrian as of January 1, 1966 are listed. It is anticipated that further studies utilizing this data will be made due to the important influence of the Precambrian surface on later sedimentation and structure and the possibility of minerals of economic importance being present in Precambrian rocks. Specific information for each well and samples, except as noted in the tabulation, are on file and available for study …

Citellus Kimballensis, A New Late Pliocene Ground Squirrel, Douglas C. Kent

Bulletin of the University of Nebraska State Museum

A new fossil sciurid, Citellus kimballensis, is described. This new species was found in the Kimball Formation, uppermost Ogallala (very late Pliocene) at the University of Nebraska State Museum Collecting Locality Cn-1O1, northeast of Sidney, Cheyenne County, Nebraska. Characters of the dentition and skull of C. kimballensis are compared with those of other species of the genus, and with those of Cynomys.

A New Species Of Rhinoceros, Aphelops Kimballensis, From The Latest Pliocene Of Nebraska, Lloyd G. Tanner

Bulletin of the University of Nebraska State Museum

An uncrushed skull and associated skeletal elements of a very large rhinoceros are the basis for the description of a new species of Aphelops from Frontier County, Nebraska. The major differences are: the skull is much larger in most dimensions than other Aphelops; it has an extremely elevated occipital region in comparison to Aphelops mutilus; the narial notch is retracted to a point perpendicular to the center of molar one; and the teeth are more hypsodont than any other species of this genus. The sediments which yielded the skull and skeletal parts are considered to be Kimballian in …