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Full-Text Articles in Paleontology

Minerals Rock!: Improving Audience Engagement And Interest In Stem Through Enhancement Of The In-Person And Online Mineral Collection At Ursinus College, Juliette Lyons Jul 2026

Minerals Rock!: Improving Audience Engagement And Interest In Stem Through Enhancement Of The In-Person And Online Mineral Collection At Ursinus College, Juliette Lyons

Environment and Sustainability Summer Fellows

Museums are a vital source of educational resources for the general public. They provide information on a variety of topics and disciplines and encourage visitors to be excited about and engaged in learning something new. As we work to comprehend key topics such as climate change, it is especially important for the broader public to better understand science, including geology. While the geological collection at Ursinus, Pieces of Earth’s History, is not in a museum, implementing methods that museums use can improve the reception of the collection. Through the application of research gathered through articles, journals, books, and talking with …


Updates To The Caniform Fauna (Carnivora, Caniformia) Of The John Day Formation, Oregon, Usa, John D. Orcutt, Kevin C. Talbott, Michael J. Monroe, Nicholas A. Famoso Jun 2026

Updates To The Caniform Fauna (Carnivora, Caniformia) Of The John Day Formation, Oregon, Usa, John D. Orcutt, Kevin C. Talbott, Michael J. Monroe, Nicholas A. Famoso

Biology Faculty Scholarship

The John Day Formation of central Oregon preserves a diversity of Oligo-Miocene caniform carnivorans, many of which were first described from the formation. However, many historically important specimens lack detailed locality or stratigraphic information, complicating any analysis of faunal change through time. Here, we describe 16 new specimens of caniforms from the John Day Formation, most with precise stratigraphic information. We report multiple specimens of the amphicyonids Daphoenus Leidy, 1853, Paradaphoenus cuspigerus (Cope, 1878), and Temnocyon altigenis (Cope, 1878), all previously known from the formation. We also report the first definitive occurrence of the hesperocyonine canid Osbornodon Wang, 1994 from …


Segmented Inner Skull Cavities Of Eothoracosaurus Mississippiensis (Msu 3293), Amy Moe-Hoffman, Renee Clary May 2026

Segmented Inner Skull Cavities Of Eothoracosaurus Mississippiensis (Msu 3293), Amy Moe-Hoffman, Renee Clary

Research Data

Dunn-Seiler Museum specimen data:

  • Catalog Number: DSM/MSU#3293 HOLOTYPE 
  • Geographic Locality: Oktibbeha County, MS Rock Hill vicinity 
  • Geologic Locality: Ripley Formation 
  • Age: Cretaceous (Maastrichtian)   

Specimen includes Cranium, Mandible, loose teeth, and post-cranial elements.  

  1. CT Scan description: The specimen MSU 3293 was scanned at the Mississippi State University College of Veterinary Medicine using a GE LightSpeed VCT (GE Healthcare, Chicago, Illinois, USA; www.gehealthcare.com ) on May 4th 2022, with scan energies of 120kV and 200mA. This produced 1593 images with a slice thickness of 625µm. 
  2. 3D models: 3D models of segmented inner skull cavities based on segrmetation of the CT scanned …


Nebraska Statewide Groundwater-Level Monitoring Report 2025, Aaron R. Young, Mark E. Burbach, Sue Olafsen Lackey, Robert Matthew Joeckel, Jeffrey Westrop Jan 2026

Nebraska Statewide Groundwater-Level Monitoring Report 2025, Aaron R. Young, Mark E. Burbach, Sue Olafsen Lackey, Robert Matthew Joeckel, Jeffrey Westrop

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Last Glacial Maximum And Late Glacial Aeolian Sand Activity, South-Central Indiana, Usa, H. M. Loope, J. L. Antinao, P.R. Hanson, P. M. Jacobs, D. A. Grimley Jan 2026

Last Glacial Maximum And Late Glacial Aeolian Sand Activity, South-Central Indiana, Usa, H. M. Loope, J. L. Antinao, P.R. Hanson, P. M. Jacobs, D. A. Grimley

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Report 17—Revisions To The Articles Of Organization And Procedure Of The Commission On Stratigraphic Nomenclature Of The Americas, Lynn T. Dafoe, Robert B. Macnaughton, Marie-Perre Aubry, Carlton E. Brett, James R. Lehane, Fernando Núñez-Useche, Randall C. Orndorff, Frank Brunton, Lucy E. Edwards, Richard H. Fluegeman, Howard Harper, Robert Matthew Joeckel, Norman P. Lasca, B. H. Tew Jan 2026

Report 17—Revisions To The Articles Of Organization And Procedure Of The Commission On Stratigraphic Nomenclature Of The Americas, Lynn T. Dafoe, Robert B. Macnaughton, Marie-Perre Aubry, Carlton E. Brett, James R. Lehane, Fernando Núñez-Useche, Randall C. Orndorff, Frank Brunton, Lucy E. Edwards, Richard H. Fluegeman, Howard Harper, Robert Matthew Joeckel, Norman P. Lasca, B. H. Tew

Conservation and Survey Division: Faculty and Staff Publications

Several revisions to the Articles of Organization and Procedure for the North American Commission on Stratigraphic Nomenclature have been adopted following the 75th, 79th, and 80th annual meetings of the Commission in 2020, 2024 and 2025, respectively. Of these, the most substantial change was revision of Article III regarding membership composition of the Commission and the addition of new member organizations from Central and South America and the Caribbean region. As a result, the Commission also voted to change its name to be more inclusive of the expanding membership, with approval of the name: Commission on Stratigraphic Nomenclature of the …


What Does Graptolite Origination And Extinction Reveal About The Cause Of The Late Ordovician Mass Extinction?, Charles E. Mitchell, H. David Sheets, Michael J. Melchin, Chris Holmden Dec 2025

What Does Graptolite Origination And Extinction Reveal About The Cause Of The Late Ordovician Mass Extinction?, Charles E. Mitchell, H. David Sheets, Michael J. Melchin, Chris Holmden

Computer and Data Science Faculty Publications

Assesses the macroevolutionary turnover of paleotropical planktic graptolites during the Late Ordovician Mass Extinction (LOME) via automated sequencing and capture-mark-recapture modeling. Graptolites exhibited a succession of turnover pulses (sensu Elizabeth Vrba) that were coincident with the main phases of the Hirnantian glaciation and during which the Diplograptina experienced declining metapopulation size, elevated extinction, zero species originations, and ultimately, complete extermination. Concurrently, the Neograptina (latest Katian temperate zone immigrants) exhibit pulses of both extinction and adaptive radiation. Thus, the LOME involved intense species selection and the wholesale alteration of the clade diversity structure of a major element of the zooplankton. The …


Global, Continental, And Local Scale Paleoenvironmental Reconstruction Methods For Interpreting The History Of Miocene North America And The Great Plains, Willow Hue Nguy Dec 2025

Global, Continental, And Local Scale Paleoenvironmental Reconstruction Methods For Interpreting The History Of Miocene North America And The Great Plains, Willow Hue Nguy

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The Miocene of North America is characterized by dynamic changes in herbivore communities, habitat composition, and global climate. Long-term cooling and drying trends influenced large changes in floral and faunal communities. The Great Plains, North America shifted from closed-canopy biomes to open-canopy biomes with C3-grasses to biomes with C4-grasses. This shift affected the herbivore communities as browsing-adapted ungulates were replaced by grazing-adapted ungulates. Much focus has centered on the Great Plains, so it is not well understood how the changes in biomes compare to other regions of North America. The models used for vegetation density indicate open-canopy biomes since at …


Dental Microwear And Diets Of Late Miocene Primates From Rudabánya, Hungary, Peter S. Ungar, Anna K. Wilcox, David R. Begun Sep 2025

Dental Microwear And Diets Of Late Miocene Primates From Rudabánya, Hungary, Peter S. Ungar, Anna K. Wilcox, David R. Begun

School of Dentistry Faculty Publications

Objectives: This study focuses on a dental microwear texture analysis of European pliopithecids and dryopithecins from the Miocene primate site of Rudabánya, Hungary. The goal is to determine whether these taxa, found in part together in the same deposits, differed in their food preferences, or at least consumed, on a daily basis, in a manner that might have facilitated sympatry. Materials and Methods: Here we report on a molar surface texture analysis of all available fossil primates from Rudabánya that preserve antemortem microwear. This includes both Anapithecus hernyaki (n = 14) and Rudapithecus hungaricus (n = 5, including one from …


Collaborative Research: Bocp-Implementation: Us-China: Multi-Scale, Multi- Proxy, Integrative Investigation Of Functional Biodiversity On A Changing Proterozoic Planet, Carol Dehler Aug 2025

Collaborative Research: Bocp-Implementation: Us-China: Multi-Scale, Multi- Proxy, Integrative Investigation Of Functional Biodiversity On A Changing Proterozoic Planet, Carol Dehler

Funded Research Records

No abstract provided.


A Multi-Isotope Investigation Of Mammoth Diet, Habitat, And Movement Patterns In The Central Great Plains, U.S.A., Jacob Mccloskey Aug 2025

A Multi-Isotope Investigation Of Mammoth Diet, Habitat, And Movement Patterns In The Central Great Plains, U.S.A., Jacob Mccloskey

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

During the Last Glacial Maximum (LGM), the Great Plains in Nebraska consisted of wooded parklands and grasslands, whereas spruce (Picea) forests, parklands, and steppe grasslands dominated east of the Missouri River. I analyzed bulk carbon (δ13C), oxygen (δ18O), and strontium (87Sr/86Sr) isotopes from tooth enamel in isolated mammoth (Mammuthus) molars to compare diet and movement patterns in two late Pleistocene assemblages: one in Nebraska (n = 24), and one in western Iowa and Missouri (n = 17). Furthermore, I identified a morphometric subset of molars as …


Groundwater In Nebraska, Troy E. Gilmore, Jesse T. Korus Dr. Jul 2025

Groundwater In Nebraska, Troy E. Gilmore, Jesse T. Korus Dr.

Conservation and Survey Division: Faculty and Staff Publications

What is groundwater? Groundwater is water that fills and moves between spaces in underground rocks, gravel, sand, or other materials.


The Petm: A Window Into Earth's Future Climate, Jacalyn M. Wittmer Malinowski May 2025

The Petm: A Window Into Earth's Future Climate, Jacalyn M. Wittmer Malinowski

Climate Change and the Individual, 2025-26

The Paleocene-Eocene Thermal Maximum (PETM) is not just an event that occurred in Earth’s distant past (~55 million years ago) but is a crucial lesson for today’s meteoric climate change. The PETM offers a historical parallel of rapid flux of greenhouse gases into the atmosphere that caused global warming, ocean acidification, dramatic changes in weather, and extinctions. This global warming event was the result of 20,000 years of “rapid” warming (in geological terms) however, we are experiencing rates of warming that are 5-10x higher than PETM levels. We are not experiencing rapid warming today, in comparison to the past, we …


The Human Legacy: Agriculture, Civilizations, Strife, And Pandemics Changing Our Climate, Jacalyn M. Wittmer Malinowski May 2025

The Human Legacy: Agriculture, Civilizations, Strife, And Pandemics Changing Our Climate, Jacalyn M. Wittmer Malinowski

Climate Change and the Individual, 2025-26

For most of human history, climate has shaped our lives, while our influence on it remained minimal. However, the notion that early humans had no measurable impact on the climate before industrialization is inaccurate. Early in human history, activities – such as the rise of agriculture, the growth of civilizations, periods of conflict, and pandemics – altered greenhouse gas levels in the atmosphere. These changes contributed to significant periods of climate change long before the burning of fossil fuels set us on the path to today’s global climate crisis.


Older Groundwater Reservoirs In Nebraska, Marvin P. Carlson, Steven S. Sibray Apr 2025

Older Groundwater Reservoirs In Nebraska, Marvin P. Carlson, Steven S. Sibray

Conservation and Survey Division: Faculty and Staff Publications

Sedimentary rocks below Nebraska's regional water table are saturated down to the crystalline igneous and metamorphic rocks of Precambrian age. The total thickness of these sedimentary rocks ranges from about 600 feet to over 10,000 feet. Nearly all current wells in Nebraska produce water from the near-surface, unconsolidated or partly consolidated rocks. Most studies to date -- interpretive reports, test drilling, inventory of wells, monitoring water levels, and water quality determinations -- have concentrated on these near-surface sources of groundwater.


Primates From Senèze, Eric Delson Apr 2025

Primates From Senèze, Eric Delson

Publications and Research

Senèze has yielded two primate fossils, neither from the recent field work. A partial ulna can be identified as cf. Macaca sylvanus. A nearly complete female skull is the holotype of Dolichopithecus arvernensis Depéret, 1928, now included in Paradolichopithecus. Emended and differential diagnoses are provided for this genus and species for the first time, and the Senèze skull is described and briefly compared to those of other species of the genus. Dental and cranial measurements are provided, along with comparative data. The macaque and Paradolichopithecus are moderately to highly terrestrial, respectively, and they suggest a woodland to more open …


Stratigraphy And Osl Chronology Of Lunette Deposits Indicates That Nebraska’S Rainwater Basins Formed By Aeolian Deflation Between 39 And 25 Ka, P.R. Hanson, Robert Matthew Joeckel Jan 2025

Stratigraphy And Osl Chronology Of Lunette Deposits Indicates That Nebraska’S Rainwater Basins Formed By Aeolian Deflation Between 39 And 25 Ka, P.R. Hanson, Robert Matthew Joeckel

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Microbial Mats In Dinosaur Ichnocoenoses, Nora Noffke, Paul C. Murphey, Roger C. Buntin, Martin G. Lockley Jan 2025

Microbial Mats In Dinosaur Ichnocoenoses, Nora Noffke, Paul C. Murphey, Roger C. Buntin, Martin G. Lockley

OES Faculty Publications

Until now, the significance of microbial mats in preservation of dinosaur tracks and in reconstructing the palaeoenvironment in which dinosaurs roamed was rarely studied. Dinosaur tracks are commonly found close to ancient aquatic bodies where moist sediment had once allowed footstep registration. At such sites, epibenthic or endobenthic microbial mats may have developed as well and may have led to exquisite track preservation. Microbial mats in coastal, lacustrine or flood plain environments cause ‘microbially induced sedimentary structures—MISS’, which are micobialites found in sandy or evaporitic settings. The microbial structures record environmental parameters including meteorological conditions that existed at the time …


Early Holocene Interaction Of Aeolian, Alluvial, And Lacustrine Processes In A Dune-Dammed Valley In The Central Nebraska Sand Hills, Gpsia Mahoney, R. D. Mandel, P.R. Hanson, Sherilyn Fritz Jan 2025

Early Holocene Interaction Of Aeolian, Alluvial, And Lacustrine Processes In A Dune-Dammed Valley In The Central Nebraska Sand Hills, Gpsia Mahoney, R. D. Mandel, P.R. Hanson, Sherilyn Fritz

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Conservation And Survey Division 2024 Annual Report, R.M. Joeckel, Michele Waszgis Jan 2025

Conservation And Survey Division 2024 Annual Report, R.M. Joeckel, Michele Waszgis

Conservation and Survey Division: Faculty and Staff Publications

The Conservation and Survey Division of the University of Nebraska - Lincoln is the agency designated by statute to investigate and interpret the geologically related natural resources of the State, to make available to the public the results of these investigations, and to assist in the development and conservation of these resources. It consists of program areas in geology, water, soils and remote sensing-geographic information systems.


Traittrainr: Accelerating Large-Scale Simulation Under Models Of Continuous Trait Evolution, Jenniffer Roa Lozano, Mataya Duncan, Duane D. Mckenna, Todd A. Castoe, Michael Degiorgio, Richard Adams Dec 2024

Traittrainr: Accelerating Large-Scale Simulation Under Models Of Continuous Trait Evolution, Jenniffer Roa Lozano, Mataya Duncan, Duane D. Mckenna, Todd A. Castoe, Michael Degiorgio, Richard Adams

Entomology and Plant Pathology Faculty Publications and Presentations

Abstract

Motivation

The scale and scope of comparative trait data are expanding at unprecedented rates, and recent advances in evolutionary modeling and simulation sometimes struggle to match this pace. Well-organized and flexible applications for conducting large-scale simulations of evolution hold promise in this context for understanding models and more so our ability to confidently estimate them with real trait data sampled from nature. Results

We introduce TraitTrainR, an R package designed to facilitate efficient, large-scale simulations under complex models of continuous trait evolution. TraitTrainR employs several output formats, supports popular trait data transformations, accommodates multi-trait evolution, and exhibits flexibility …


Tooth Type And Position In A Hypothetical Pectinodon..., Keith Snyder, Jonathon Campos, Neal Doran, Charity Simmons Sep 2024

Tooth Type And Position In A Hypothetical Pectinodon..., Keith Snyder, Jonathon Campos, Neal Doran, Charity Simmons

Achieve

In 1856, Leidy rst identied Troodontidae as a taxonomic unit. It was not until 1945 that C.M. Sternberg assigned it to a family status. There has been much debate on taxonomic naming in this family, but in 1987, Currie conated all previous names into a single species, Troodon formosus. On the basis of isolated teeth, Carpenter (1982) suggested a second species, Pectinodon bakkeri from the Lance Formations. With limited specimens (24), Longrich (2008) proposed tooth positioning for the 4 tooth types he dened. This was especially challenging since no cranial or post-cranial skeletal structures have yet been identied.

Over the …


Biostratigraphic Revision Of Esthonyx (Tillidontia, Mammalia) In The Contect Of Climate Change In The Lower Eocene Of The Bighorn Basin, Wyoming, John Colter Johnson Jul 2024

Biostratigraphic Revision Of Esthonyx (Tillidontia, Mammalia) In The Contect Of Climate Change In The Lower Eocene Of The Bighorn Basin, Wyoming, John Colter Johnson

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

Esthonyx is an early Eocene tillodont found in North America, Europe, and India. The genus was named by Edward Drinker (E. D.) Cope in 1874 based on specimens from the San Jose Formation in New Mexico. Since then, several species of Esthonyx have been described from North America alone. The best record of Esthonyx comes from the central Bighorn Basin (BHB) in Wyoming, where it appears in 220 localities in a 640 m-thick stratigraphic succession. Since the last summary of Esthonyx in the BHB, several hundred new specimens have been collected and curated at the Denver Museum of Nature and …


Phylogeny And Disparity Of Ammonoid Family Acanthoceratidae Over Ocean Anoxic Event 2, Lindsey Howard Jul 2024

Phylogeny And Disparity Of Ammonoid Family Acanthoceratidae Over Ocean Anoxic Event 2, Lindsey Howard

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

The widespread use of genera as proxies for species in paleobiological studies might affect the results of these studies. Although most attention has been given to taxonomic diversity studies, this could also be true of disparity and phylogenetic studies. In particular, the assumption that particular character states truly diagnose all members of a genus might distort results. This study examines the disparity of Acanthoceratid ammonoids at both the generic and species level. 149 species from 42 genera were examined with 52 characters measured. Following the measurements, an inverse modeling simulation was run 100 times to generate a simulated phylogeny with …


Theory Of An Automatic Seepage Meter And Ramifications For Applications, V. A. Zlotnik, D. K. Solomon, D. P. Genereux, T. E. Gilmore, C. E. Humphrey, A. R. Mittelstet, A. V. Zlotnik May 2024

Theory Of An Automatic Seepage Meter And Ramifications For Applications, V. A. Zlotnik, D. K. Solomon, D. P. Genereux, T. E. Gilmore, C. E. Humphrey, A. R. Mittelstet, A. V. Zlotnik

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Controls On Soft Tissue And Cellular Preservation In Late Eocene And Oligocene Vertebrate Fossils From The White River And Arikaree Groups Of Nebraska, South Dakota, And Wyoming, John E. Gallucci, Grace Woolslayer, Kelsey Barker, Brian Kibelstis, Allison R Tumarkin-Deratzian, Paul V. Ullmann, David E. Grandstaff, Dennis O. Terry May 2024

Controls On Soft Tissue And Cellular Preservation In Late Eocene And Oligocene Vertebrate Fossils From The White River And Arikaree Groups Of Nebraska, South Dakota, And Wyoming, John E. Gallucci, Grace Woolslayer, Kelsey Barker, Brian Kibelstis, Allison R Tumarkin-Deratzian, Paul V. Ullmann, David E. Grandstaff, Dennis O. Terry

School of Earth & Environment Departmental Research

Previous studies on microtaphonomy have identified multiple types of organic microstructures in fossil vertebrates from a variety of time periods and past environmental settings. This study investigates potential taphonomic, paleoenvironmental, and paleoclimatic controls on soft tissue and cellular preservation in fossil bone. To this end, fifteen vertebrate fossils were studied: eight fossils collected from the Oligocene Sharps Formation of the Arikaree Group in Badlands National Park, South Dakota, and seven fossils from formations in the underlying White River Group, including the Oligocene Brule Formation of Badlands National Park, and the Eocene Chadron Formation of Flagstaff Rim, Wyoming; Toadstool Geologic Park, …


Ecological Dynamics Of Cenozoic North American Mammals, Alexandria Brandis Shupinski May 2024

Ecological Dynamics Of Cenozoic North American Mammals, Alexandria Brandis Shupinski

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Understanding how community structure is affected by various ecological, climatic, and environmental changes is a long-standing goal in ecology. However, disentangling human impacts from these other variables is difficult when using short modern timescales and anthropogenically altered communities. The fossil record provides a means to investigate community structure dynamics across critical intervals, excluding humans as a variable. Here, in three studies, I assess changes in North American mammal paleocommunity structure across the last 66 million years (Ma) at multiple temporal and spatial scales. In Chapter 1, I identify changes in mammal functional diversity (FD) locally and continentally, using three independent …


Consequences Of The Megafauna Extinction: Changes In Food Web Networks On The Edwards Plateau Across The Pleistocene–Holocene Transition, Quentin A. Smith Jr. May 2024

Consequences Of The Megafauna Extinction: Changes In Food Web Networks On The Edwards Plateau Across The Pleistocene–Holocene Transition, Quentin A. Smith Jr.

School of Biological Sciences: Dissertations, Theses, and Student Research

We are experiencing biodiversity loss due to climate change and human impacts, which is not only harmful to the environment but can also alter the composition of communities and interactions among species. The late Pleistocene experienced a loss of large-bodied mammals which resulted in significant changes in community structure due to changes in body size, diet, and species associations. The impact of these changes on species interactions and community structure across the Pleistocene-Holocene transition remains poorly understood. Using a robust data set of species composition, stable isotopes, body size, and climate variables, we constructed and compared ecological networks of mammal …


New Vertebrate Microfossils Expand The Diversity Of The Chondrichthyan And Actinopterygian Fauna Of The Maastrichtian–Danian Hornerstown Formation In New Jersey, Zachary Boles, Paul V. Ullmann, Ian Putnam, Mariele Ford, Joseph T. Deckhut Apr 2024

New Vertebrate Microfossils Expand The Diversity Of The Chondrichthyan And Actinopterygian Fauna Of The Maastrichtian–Danian Hornerstown Formation In New Jersey, Zachary Boles, Paul V. Ullmann, Ian Putnam, Mariele Ford, Joseph T. Deckhut

School of Earth & Environment Departmental Research

The abundance of shark and actinopterygian fossils in the Cretaceous and Paleogene strata of the Atlantic Coastal Plain is well documented; but much remains unknown about the survivorship patterns of these major components of shallow marine faunas in the western Atlantic through the K/Pg mass extinction. To shed light on this subject, we describe an assemblage of new actinopterygian, chondrichthyan, and reptilian microfossils recently recovered from the Maastrichtian Navesink and Maastrichtian–Danian Hornerstown formations at the Jean and Ric Edelman Fossil Park at Rowan University in Mantua Township, New Jersey. The new microfossils clarify extinction patterns across the K/Pg, create temporal …


Paradox Lost: Wide Gape In The Ordovician Brachiopod Rafinesquina Explains How Unattached Filter-Feeding Strophomenoids Thrived On Muddy Substrates, Benjamin F. Dattilo, Rebecca L. Freeman, Kyle Hartshorn, David Peterman, Aaron Morse, David L. Meyer, Lindsay G. Dougan, James W. Hagadorn Apr 2024

Paradox Lost: Wide Gape In The Ordovician Brachiopod Rafinesquina Explains How Unattached Filter-Feeding Strophomenoids Thrived On Muddy Substrates, Benjamin F. Dattilo, Rebecca L. Freeman, Kyle Hartshorn, David Peterman, Aaron Morse, David L. Meyer, Lindsay G. Dougan, James W. Hagadorn

Earth and Environmental Sciences Faculty Publications

Strophomenoid brachiopods had thin, concavo-convex shells, were ubiquitous colonizers of Palaeozoic muddy seafloors, and are hypothesized to have filter-fed in a concave-upward orientation. This orientation would elevate their line of commissure out of potentially lethal lophophore-clogging mud. The paradox is that epi- biont distributions on strophomenoids support a convex-upward life position, as do studies of strophome- noid stability and trace fossils formed by strophomenoid sediment-clearing. A premise of the concave-upward orientation hypothesis is a narrow gape, which causes narrow, high velocity inhalant currents, leaving strophomenoids vul- nerable to sediment entrainment. Herein we investigate the gape angle of Rafinesquina using serial …