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Full-Text Articles in Paleobiology

Shallow-Marine Crinoid Genera May Have Been More Resilient Across Permian Extinction Events In Terms Of Richness Than Deep-Marine Crinoid Genera, Amelia C. Kolstad Jun 2026

Shallow-Marine Crinoid Genera May Have Been More Resilient Across Permian Extinction Events In Terms Of Richness Than Deep-Marine Crinoid Genera, Amelia C. Kolstad

University Honors Theses

Throughout the Phanerozoic, one of the most successful phyla of marine invertebrates has been Echinodermata. Echinodermata was particularly successful throughout the Paleozoic, with class Crinoidea making up a majority of occurrences. The proportion of echinoderm occurrences that are crinoids declined massively at the end of the Permian and continued to decrease into modern day, never fully recovering. One of the factors thought to have been so important for crinoid success in the Paleozoic and their decreasing success throughout geologic time has been their propensity for success in shallow-marine environments, though crinoids also exist within deep-marine environments. This study seeks to …


Mumm Vs. Minium: A Tale Of Two Quarries, Kale Link, Amanda Peng Apr 2026

Mumm Vs. Minium: A Tale Of Two Quarries, Kale Link, Amanda Peng

SACAD: Scholarly Activities

In 2025, a discrepancy was discovered in the field numbers of a selection of mammal fossils, which had been mistakenly catalogued as originating from the Minium Quarry in Graham County, KS instead of the Mumm Quarry in Rawlins County, KS. While both quarries belong to the Ogallala Formation, they demonstrate differing biostratigraphic ages, faunal assemblages, and taphonomic settings. Mumm is Clarendonian aged, while Minium is Hemphillian. To correct this issue, all the Mumm specimens were assigned to an updated locality with more precise geographic and biostratigraphic data.


Distribution And Tooth Morphoguilds Of Mosasaurids (Squamata) Of The Campanian Western Interior Seaway With Implications For Controls On Mosasaur Paleobiogeography, Alec Zaborniak Jan 2025

Distribution And Tooth Morphoguilds Of Mosasaurids (Squamata) Of The Campanian Western Interior Seaway With Implications For Controls On Mosasaur Paleobiogeography, Alec Zaborniak

Master's Theses or Doctor of Nursing Practice

The Western Interior Seaway (WIS) of North America is well known for its mosasaurid squamate diversity, particularly during the Campanian of the Late Cretaceous. Mosasaurid diversity has historically been examined at a fine scale, with many studies investigating the faunal composition of specific assemblages; however, studies focusing on mosasaur communities within the Western Interior Seaway during specific Ages are currently lacking. Mosasaur tooth morphology has also been extensively studied, with tooth characteristics commonly being used as phylogenetic characters. However, many studies examining mosasaur communities and tooth morphology have been focused on broader spatiotemporal or phylogenetic scales. This study investigates the …


Assessing Unstable Fossils For Long-Term Storage, Carson Cope, Alex Landwehr, Kale Link, Israel Rivera-Molina, Laura E. Wilson Apr 2024

Assessing Unstable Fossils For Long-Term Storage, Carson Cope, Alex Landwehr, Kale Link, Israel Rivera-Molina, Laura E. Wilson

SACAD: Scholarly Activities

In 2022, Fort Hays State University’s Sternberg Museum of Natural History (FHSM) began a project to address the long-term preservation of a Late Miocene mammal collection. Many of the fossils from the collection were poorly consolidated, uncurated, and improperly stored, leaving them unstable and prone to significant degradation. To organize our stabilization efforts, we developed a new assessment workflow consisting of two evaluation tools. These tools have helped us categorize the risk factors for specimens, the priority in which they should be addressed, and how to store the fossils long-term. With these newly developed workflows, we are in a better …


Timing Of Diversification, Dispersal, And Biogeography Of Parrots In The Genus Amazona (Psittaciformes: Psittacidae) Throughout The Caribbean, Visualized In Gis, Christopher Kingwill Jan 2023

Timing Of Diversification, Dispersal, And Biogeography Of Parrots In The Genus Amazona (Psittaciformes: Psittacidae) Throughout The Caribbean, Visualized In Gis, Christopher Kingwill

Master's Theses or Doctor of Nursing Practice

Avian fossil records from across the Caribbean (Greater and Lesser Antilles) demonstrate higher avian diversity prior to extinction events due to climate change at the end of the Pleistocene and human impact across the Caribbean throughout the Holocene. Amazon parrots (Amazona) are a diverse genus of New World parrots found throughout Central and South America, as well as the Caribbean. Their phylogeny and evolutionary history, specifically for Caribbean species, has been debated in terms of source areas in Central and South America and the timing of and number of colonization events to different islands that preceded diversification into …


Reconstructing The Ecological Relationships Of Late Cretaceous Antarctic Dinosaurs And How Functional Tooth Morphology Influenced These Relationships, Ian D. Broxson May 2022

Reconstructing The Ecological Relationships Of Late Cretaceous Antarctic Dinosaurs And How Functional Tooth Morphology Influenced These Relationships, Ian D. Broxson

2022 Symposium

The Sandwich Bluff Formation of the James Ross Basin of Antarctica has recently yielded a group of five late Cretaceous dinosaurs that lived contemporaneously with each other, a first for Antarctica. These five dinosaurs include fragmentary remains of two differently sized elasmarian ornithopods, a possible megaraptor, a hadrosaur, and a nodosaur. In this study we will construct a model of the ecological relationships of late Cretaceous Antarctica. Additionally, we will look at what specific factors allowed this group of four herbivores and a carnivore to coexist in a restricted locality and what niches were filled by each species. Methods to …


Ontogenetic Niche Shift As A Driver Of Community Structure And Diversity In Non-Avian Dinosaurs, Katlin M. Schroeder May 2022

Ontogenetic Niche Shift As A Driver Of Community Structure And Diversity In Non-Avian Dinosaurs, Katlin M. Schroeder

Biology ETDs

As some of the most charismatic megafauna to ever walk the earth, the physiology, morphology, growth and evolution of non-avian theropods has been studied exhaustively, yet little is understood about their roles in ecosystems as juveniles. For carnivorous megatheropods, which exceed 1,000kg in mass yet hatched from eggs of limited size, the likelihood of utilizing different prey through ontogeny was high, simply by proxy of the immense difference in size between adults and juveniles. We found these ontogenetic niche shifts, evidenced by significantly different dental microwear in Tyrannosaurids, to have excluded dinosaurian mesocarnivores from Mesozoic communities. The few dinosaurian mesocarnivores …


Terrestrial Soldier Crab (Coenobita Clypeatus, Fabricius 1787) And Cerion Spp. (Röding 1798) Shell Relationship On San Salvador Island, Bahamas, Harley Hunt May 2021

Terrestrial Soldier Crab (Coenobita Clypeatus, Fabricius 1787) And Cerion Spp. (Röding 1798) Shell Relationship On San Salvador Island, Bahamas, Harley Hunt

Biology Theses

The Caribbean terrestrial soldier crab, Coenobita clypeatus(Fabricius 1787), coexist and utilize the shells of numerous species of land and marine gastropods. Soldier crabs rely on gastropod shells for protection as the crabs have a soft abdomen, leaving them vulnerable for predation and desiccation, threatening their survival. This creates a strong pressure to obtain well-fitting shells that provide adequate protection against water loss. Cerion of Röding (1798) shells are one of the most commonly used shells among living colonies of C. clypeatuson San Salvador Island. This study is interested in the frequency of shell use by C. clypeatus crabs …


Taphonomy Of Late Jurassic (Tithonian) Morrison Formation Apatosaurus Sp. Vertebrae Found Associated With Teeth From Allosaurus Sp. And Ceratosaurus Sp., And Body Size Extrapolation From The Associated Theropod Teeth., Greg C. Agyan May 2021

Taphonomy Of Late Jurassic (Tithonian) Morrison Formation Apatosaurus Sp. Vertebrae Found Associated With Teeth From Allosaurus Sp. And Ceratosaurus Sp., And Body Size Extrapolation From The Associated Theropod Teeth., Greg C. Agyan

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

An Apatosaurus sp. locality from Dinosaur National Monument designated DNM-15 was excavated in 1985, and associated with two Allosaurus teeth and one Ceratosaurus tooth that were near one of the caudal vertebrae. The Ceratosaurus tooth was buried between an overlying rib and that same caudal vertebra. The caudal vertebrae of the DNM-15 Apatosaurus were intact and articulated, but the anterior skeleton was mostly absent, with a row of articulated sacral vertebrae in close association with a femur. Two other Allosaurus teeth were reported near the preserved ilium of the Apatosaurus, but they could not be located in the collections. …


An Unusual Mastodon Revisited: Providing A Regional Focus For Mammut Americanum (Proboscidea, Mammutidae) In The Southeast, Matthew Inabinett May 2020

An Unusual Mastodon Revisited: Providing A Regional Focus For Mammut Americanum (Proboscidea, Mammutidae) In The Southeast, Matthew Inabinett

Electronic Theses and Dissertations

A century ago, two large American mastodon Mammut americanum specimens from coastal South Carolina were mounted for display at Amherst College. Their robust build, broad and pentalophodont third molars, and well-developed mandibular tusks were noted as unusual. Here, these specimens are redescribed; three additional mastodon mandibles from the same region of South Carolina are also described. Though collection information on these specimens is sparse, they appear to span >150 ka in the Middle to Late Pleistocene, and probably include the first report of Mammut from the earliest-Rancholabrean Ten Mile Hill Formation. Some “unusual” features — moderately to extremely broad third …


An Assessment Of Convergence In The Feeding Morphology Of Xiphactinus Audax And Megalops Atlanticus Using Landmark-Based Geometric Morphometrics, Edward Chase Shelburne Jan 2020

An Assessment Of Convergence In The Feeding Morphology Of Xiphactinus Audax And Megalops Atlanticus Using Landmark-Based Geometric Morphometrics, Edward Chase Shelburne

Master's Theses or Doctor of Nursing Practice

Convergence is an evolutionary phenomenon wherein distantly related organisms independently develop features or functional adaptations to overcome similar environmental constraints. Historically, convergence among organisms has been speculated or asserted with little rigorous or quantitative investigation. More recent advancements in systematics has allowed for the detection and study of convergence in a phylogenetic context, but this does little to elucidate convergent anatomical features in extinct taxa with poorly understood evolutionary histories. The purpose of this study is to investigate one potentially convergent system—the feeding structure of Xiphactinus audax (Teleostei: Ichthyodectiformes) and Megalops atlanticus (Teleostei: Elopiformes)—using a comparative anatomical approach to assess …


Identifying Dietary And Migratory Patterns Of Illinois Woolly Mammoth Populations Using Isotope Analysis Of Carbon, Oxygen, And Strontium, Matthew Harrington, Chris Widga, Al Wanamaker, Doug Walker Jun 2019

Identifying Dietary And Migratory Patterns Of Illinois Woolly Mammoth Populations Using Isotope Analysis Of Carbon, Oxygen, And Strontium, Matthew Harrington, Chris Widga, Al Wanamaker, Doug Walker

Celebration of Learning

The extinct woolly mammoth (Mammuthus primigenius) ranged from Alaska to the Northeastern Seaboard throughout the Late Pleistocene (100-10 Ka). Although it is recognized that woolly mammoths coincided with and lived in a region heavily influenced by glacial ice sheets, little is known about their dietary or migratory behavior. This study classifies and provides insight into the diet and mobility of Midwestern mammoths by analyzing stable isotopes of carbon, oxygen, and strontium preserved in the tooth enamel of these extinct elephantids. A woolly mammoth tooth from Moline, IL, was bulk-sampled and micromilled to extract the aforementioned isotopes from the …


Crossed Tracks: Mesolimulus, Archaeopteryx, And The Nature Of Fossils, Leonard Finkelman Jan 2019

Crossed Tracks: Mesolimulus, Archaeopteryx, And The Nature Of Fossils, Leonard Finkelman

Faculty Publications

Organisms leave a variety of traces in the fossil record. Among these traces, vertebrate and invertebrate paleontologists conventionally recognize a distinction between the remains of an organism’s phenotype (body fossils) and the remains of an organism’s life activities (trace fossils). The same convention recognizes body fossils as biological structures and trace fossils as geological objects. This convention explains some curious practices in the classification, as with the distinction between taxa for trace fossils and for tracemakers. I consider the distinction between “parallel taxonomies,” or parataxonomies, which privileges some kinds of fossil taxa as “natural” and others as “artificial.” The motivations …


Betting & Hierarchy In Paleontology, Leonard Finkelman Jan 2019

Betting & Hierarchy In Paleontology, Leonard Finkelman

Faculty Publications

In his Rock, Bone, and Ruin: An Optimist’s Guide to the Historical Sciences, Adrian Currie argues that historical scientists should be optimistic about success in reconstructing the past on the basis of future research. This optimism follows in part from examples of success in paleontology. I argue that paleontologists’ success in these cases is underwritten by the hierarchical nature of biological information: extinct organisms have extant analogues at various levels of taxonomic, ecological, and physiological hierarchies, and paleontologists are adept at exploiting analogies within one informational hierarchy to infer information in another. On this account, fossils serve the role …


Evaluating Stable Isotope And Geochronologic Techniques For Paleoclimate Reconstruction: Case Study Of The Santa Cruz Formation, Argentina, Robin B. Trayler Dec 2018

Evaluating Stable Isotope And Geochronologic Techniques For Paleoclimate Reconstruction: Case Study Of The Santa Cruz Formation, Argentina, Robin B. Trayler

Boise State University Theses and Dissertations

Stable isotope analysis has become the method of choice for many studies investigating the paleoecology and paleoclimate of fossil mammal faunas. While organic tissues (collagen, keratins, proteins) persist for < 105 years highly mineralized tooth enamel is resistant to alteration and degradation and faithfully preserves its isotopic composition for millions (> 106) years. Reconstructing past climates from these records relies on both understanding both micro-scale mechanisms of isotope incorporation into individual teeth, and macro-scale changes in isotope compositions over hundreds of thousands or millions of years. In this dissertation I address three questions.

First, how does the geometry and …


Redescription And Phylogenetic Analysis Of The Materials Assigned To The Taxon "Captorhinikos" Chozaensis, Jason Paul Jung Mar 2018

Redescription And Phylogenetic Analysis Of The Materials Assigned To The Taxon "Captorhinikos" Chozaensis, Jason Paul Jung

Electronic Theses, Projects, and Dissertations

“Captorhinikos” chozaensis is a multiple-tooth-rowed captorhinid reptile from the Lower Permian Clear Fork Group, undivided formation. Upon re-examination of the materials associated with the species from both the Chicago Field Museum of Natural History, and the Smithsonian United States National Museum, I reaffirm their affinity and collective identity as a valid taxon. “Captorhinikos” chozaensis does not, however, belong with either of the two members of its genus, C. valensis or “C.” parvus, instead occupying its own branch on the phylogenetic tree of the Captorhinidae. This conclusion is based in strong results from a combined phylogenetic parsimony analysis combined with …


A Quantitative Analysis Of Intermediate Forms Within Astarte From The Atlantic Coastal Plain, Philip Roberson Jan 2018

A Quantitative Analysis Of Intermediate Forms Within Astarte From The Atlantic Coastal Plain, Philip Roberson

Murray State Theses and Dissertations

The Atlantic Coastal Plain has long been recognized as a natural laboratory useful for testing hypotheses about various environmental and ecological effects on marine fauna. For studies such as these to continue being conducted in a rigorous and easily repeatable manner, a reliable taxonomy must be established for genera within this physiographic province. The bivalve genus, Astarte, is a cosmopolitan genus that is commonly found within the Atlantic Coastal Plain. This genus has many formally recognized species, even though it lacks many features that would encourage diversification, marking it as a taxonomic group in need of potential revision. The …


Middle Miocene Paleoenvironmental Reconstruction Of The Central Great Plains From Stable Carbon Isotopes In Large Mammals, Willow H. Nguy Jul 2017

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 …


Paleoimagery: The Artistic Restoration Of Dinosaurs And Prehistoric Life, Colin Mcnulty May 2017

Paleoimagery: The Artistic Restoration Of Dinosaurs And Prehistoric Life, Colin Mcnulty

Honors Projects

My purpose in creating this paper is to research a holistic view of paleontological illustration (also called paleoimagery or paleoart). A thorough history of paleoimagery is outlined from its roots in biblical illustration in the 17th and 18th centuries approaching the modern day. A two-fold examination of the utility of art to communicate science and its use within the science of paleontology is also given. This includes discussions of the specific components of art pieces that help them to successfully communicate scientific ideas and examples of how paleoimagery contributes to paleontology. The author then outlines the conception and …


Constraining Neogene Temperature And Precipitation Histories In The Central Great Plains Using The Fossil Record Of Alligator, Evan Whiting Apr 2016

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 …


Paleoclimate Implications From Stable Isotope Analysis Of Sedimentary Organic Carbon And Vertebrate Fossils From The Cedar Mountain Formation, Ut, U.S.A., Garrett Andrew Hatzell Jul 2015

Paleoclimate Implications From Stable Isotope Analysis Of Sedimentary Organic Carbon And Vertebrate Fossils From The Cedar Mountain Formation, Ut, U.S.A., Garrett Andrew Hatzell

Graduate Theses and Dissertations

Oxygen and carbon isotopic compositions of fossilized vertebrate teeth and bone were analyzed to determine isotopic values of vertebrate faunal diet from the early Cretaceous Cedar Mountain Formation of Utah. Results for δ18O of PO4 (δ18Op) (Suarez et al., 2014) from the same data set have been compared to the δ18O of CO3 (δ18Oc) portion of teeth and turtle shell to determine if diagenetic alteration of the isotopes has occurred by plotting the line of best fit equation that models the relationship between unaltered δ18OP and δ18OC of modern mammals from Iacumin et al., 1996. Results indicate slight diagenesis of …


Late Pleistocene And Holocene Bison Of Grand Canyon And Colorado Plateau: Implications From The Use Of Paleobiology For Natural Resource Management Policy, Jeffrey M. Martin May 2014

Late Pleistocene And Holocene Bison Of Grand Canyon And Colorado Plateau: Implications From The Use Of Paleobiology For Natural Resource Management Policy, Jeffrey M. Martin

Electronic Theses and Dissertations

Bison spp. (bison) fossils are scarce on the Colorado Plateau, especially within the greater Grand Canyon region. Because of the poor fossil record for bison on the plateau and in Grand Canyon National Park, various resource managers have surreptitiously designated bison a nonnative and human-introduced species. The lack of evidence for bison seems to be the result of collection bias rather than a true lack of bison remains. Today, Grand Canyon National Park has a neighboring herd of 350 bison that have meandered unwantedly onto National Park lands from neighboring Forest Service and State of Arizona lands. This study spatiotemporally …


Cyclic Distributional Model Of The Late Moscovian Fusulinids In The Donets Basin (Ukraine) In Response To Eustatic Sea Level Fluctuations And Its Application In Biostratigraphy And Correlation, Rimma Khodjanyazova Aug 2013

Cyclic Distributional Model Of The Late Moscovian Fusulinids In The Donets Basin (Ukraine) In Response To Eustatic Sea Level Fluctuations And Its Application In Biostratigraphy And Correlation, Rimma Khodjanyazova

Boise State University Theses and Dissertations

The continuous Pennsylvanian shallow-marine, paralic, siliciclastic succession in the Donets Basin is pivotal for correlation of marine and continental strata in northern Pangaea with coeval shallow-marine mainly carbonate strata in the Moscow Basin, a historical type area of Moscovian Horizons. The details of the history of establishment, lithostratigraphy and current biostratigraphy of Podolskian and Myachkovian Horizons in the Moscow Basin that are not readily available in Western literature are reviewed.

A model of cyclic recurrence (~0.6 —1myr) of three main fusulinid assemblages in the Pennsylvanian siliciclastic-carbonate succession in the Donets Basin is proposed. A Hemifusulina-association (A) indicates the onset …


Terrestrial Vertebrate Families On Noah's Ark, Seth J. Beech Apr 2012

Terrestrial Vertebrate Families On Noah's Ark, Seth J. Beech

Senior Honors Theses

One of the central challenges faced by young-Earth creation researchers who believe the Bible to be the inerrant Word of God is defending the Biblical claim that two of every kind of nephesh animal was saved from the great flood on Noah’s ark. Recently, Answers in Genesis became involved in the design and construction of a full-sized, authentic replica of Noah’s ark. They have endeavored to be as accurate as possible in presenting the number of kinds that would have needed to be on the ark in order to have the diversity in species that we observe today. In order …


A Re-Evaluation Of The Pleistocene Hellbender, Cryptobranchus Guildayi, And An Overview Of Cryptobranchus Remains From Appalachian Caves., Keila Elaine Bredehoeft May 2010

A Re-Evaluation Of The Pleistocene Hellbender, Cryptobranchus Guildayi, And An Overview Of Cryptobranchus Remains From Appalachian Caves., Keila Elaine Bredehoeft

Electronic Theses and Dissertations

Cryptobranchus guildayi is described as an extinct species of large salamander that is closely related to the hellbender, Cryptobranchus alleganiensis. The validity of this extinct taxon has been questioned, so an expanded osteological sample of modern hellbenders was used for comparative purposes with the C. guildayi fossil material. Based on this analysis, all supposed distinguishing morphological characteristics used to define C. guildayi can be observed in specimens of C. alleganiensis, or are based on misidentifications. Therefore, Cryptobranchus guildayi is considered to be conspecific with C. alleganiensis and taxonomically should be considered a junior synonym of the latter. The …


Tertiary Coniferous Woods Of Western North America, George F. Beck Aug 1945

Tertiary Coniferous Woods Of Western North America, George F. Beck

All Faculty Scholarship for the College of the Sciences

Almost four decades have elapsed since Platen (1908), the German paleobotanist, published his report upon the fossil woods of the western United States. Since then no over-all treatment of these materials has been attempted. although Platen overlooked the Pacific Northwest with its abundance of Tertiary petrified woods. The purpose of this paper is to bring knowledge of the western coniferous woods of the Tertiary up to date. In this effort the writer recognizes that much of this information has been accumulated incidentally in the study of the Russell Petrified Forest series of central Washington, and that it is not as …


Nyssa Woods Of The Pacific-Northwest Tertiary, George F. Beck Feb 1945

Nyssa Woods Of The Pacific-Northwest Tertiary, George F. Beck

All Faculty Scholarship for the College of the Sciences

The nyssa gums are one of the modern genera of trees most certainly present among the petrified woods and forests of the Pacific Northwest. Almost every collection from the mid-Tertiary of this region contains a few specimens of typical tupelo or sour gum. These are fine-grained woods which to the unaided eye may be mistaken for conifers.


Ancient Maples Of The Central Washington Region, George F. Beck Nov 1944

Ancient Maples Of The Central Washington Region, George F. Beck

All Faculty Scholarship for the College of the Sciences

When I began work on the petrified logs of the general Vantage area some 13 years ago, it became apparent at once that maple-like woods are commonplace in the main (Vantage) raft forest and slightly less abundant in two rooted units of the Yakima Canyon. So widely do these woods range throughout the structural variations found in modern maples that little success has attended the efforts to assign them to nominal species. The extremes can readily be established but few hints exist as to the boundaries between them.


Two Newly Discovered Conifers, George F. Beck Apr 1944

Two Newly Discovered Conifers, George F. Beck

All Faculty Scholarship for the College of the Sciences

Two genera of coniferous wood, apparently not listed among the Tertiary woods of the western states, have been recognized in the Percy Train collections from Rainbow Ridge, northwestern Nevada. These two, Tsuga (hemlock) and Chamaecyparis (cedar) bring up to 14 the genera of coniferous wood more or less certainly identified from the period and area in question.


Status Of Tertiary Woods Of The Western States Representing The Juglandaceae, George F. Beck Apr 1944

Status Of Tertiary Woods Of The Western States Representing The Juglandaceae, George F. Beck

All Faculty Scholarship for the College of the Sciences

For many years there has been uncertainty concerning the generic status of some fossil leaves belonging without question to the walnut family as a whole. A review of the woods of Juglandaceae as they have appeared in Tertiary horizons of the western states has suggested which genera are present, and in what proportions their leaves (or other remains) might be expected to appear.