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Lynn Margulis And Boris Kozo-Polyansky: How The Symbiogenesis Was Translated From Russian, Victor Fet Jan 2021

Lynn Margulis And Boris Kozo-Polyansky: How The Symbiogenesis Was Translated From Russian, Victor Fet

Biological Sciences Faculty Research

This contribution details the complex history of the early work by Boris Kozo-Polyansky (1924) that became available in English translation 86 years after it was published in Russian. The great American naturalist Lynn Margulis—whose serial endosymbiosis theory was presciently predated by Kozo-Polyansky by four decades—was instrumental in organizing this resurrection and ‘horizontal transfer’ of knowledge, forgotten by that time even in Russia.


Components Of The Ribosome Biogenesis Pathway Underlie Establishment Of Telomere Length Set Point In Arabidopsis, Liliia R. Abdulkina, Callie Kobayashi, John T. Lovell, Inna B. Chastukkhina, Behailu B. Aklilu, Inna A, Agabekian, Ana V. Suescún, Lia R. Valeeva, Chuluuntsetseg Nyamsuren, Galina V. Aglyamova, Margarita R. Sharipova, Dorothy E. Shippen, Thomas E. Juenger, Eugene V. Shakirov Dec 2019

Components Of The Ribosome Biogenesis Pathway Underlie Establishment Of Telomere Length Set Point In Arabidopsis, Liliia R. Abdulkina, Callie Kobayashi, John T. Lovell, Inna B. Chastukkhina, Behailu B. Aklilu, Inna A, Agabekian, Ana V. Suescún, Lia R. Valeeva, Chuluuntsetseg Nyamsuren, Galina V. Aglyamova, Margarita R. Sharipova, Dorothy E. Shippen, Thomas E. Juenger, Eugene V. Shakirov

Biological Sciences Faculty Research

Telomeres cap the physical ends of eukaryotic chromosomes to ensure complete DNA replication and genome stability. Heritable natural variation in telomere length exists in yeast, mice, plants and humans at birth; however, major effect loci underlying such polymorphism remain elusive. Here, we employ quantitative trait locus (QTL) mapping and transgenic manipulations to identify genes controlling telomere length set point in a multi-parent Arabidopsis thaliana mapping population. We detect several QTL explaining 63.7% of the total telomere length variation in the Arabidopsis MAGIC population. Loss-of-function mutants of the NOP2A candidate gene located inside the largest effect QTL and of two other …


Using Molecular Diet Analysis To Inform Invasive Species Management: A Case Study Of Introduced Rats Consuming Endemic New Zealand Frogs, Bastian Egeter, Cailín Roe, Sara Peixoto, Pamela Puppo, Luke J. Easton, Joana Pinto, Phillip J. Bishop, Bruce C. Robertson May 2019

Using Molecular Diet Analysis To Inform Invasive Species Management: A Case Study Of Introduced Rats Consuming Endemic New Zealand Frogs, Bastian Egeter, Cailín Roe, Sara Peixoto, Pamela Puppo, Luke J. Easton, Joana Pinto, Phillip J. Bishop, Bruce C. Robertson

Biological Sciences Faculty Research

The decline of amphibians has been of international concern for more than two decades, and the global spread of introduced fauna is a major factor in this decline. Conservation management decisions to implement control of introduced fauna are often based on diet studies. One of the most common metrics to report in diet studies is Frequency of Occurrence (FO), but this can be difficult to interpret, as it does not include a temporal perspective. Here, we examine the potential for FO data derived from molecular diet analysis to inform invasive species management, using invasive ship rats (Rattus rattus) …


The Genomic Landscape Of Molecular Responses To Natural Drought Stress In Panicum Hallii., John T. Lovell, Jerry Jenkins, David B. Lowry, Sujan Mamidi, Avinash Sreedasyam, Xiaoyu Weng, Kerrie Barry, Jason Bonnette, Brandon Campitelli, Chris Daum, Sean P. Gordon, Billie A. Gould, Albina Khasanova, Anna Lipzen, Alice Macqueen, Juan Diego Palacio-Mejía, Christopher Plott, Eugene V. Shakirov, Shengqiang Shu, Yuko Yoshinaga, Matt Zane, Dave Kudrna, Jason D. Talag, Daniel Rokhsar, Jane Grimwood, Jeremy Schmutz, Thomas E. Juenger Dec 2018

The Genomic Landscape Of Molecular Responses To Natural Drought Stress In Panicum Hallii., John T. Lovell, Jerry Jenkins, David B. Lowry, Sujan Mamidi, Avinash Sreedasyam, Xiaoyu Weng, Kerrie Barry, Jason Bonnette, Brandon Campitelli, Chris Daum, Sean P. Gordon, Billie A. Gould, Albina Khasanova, Anna Lipzen, Alice Macqueen, Juan Diego Palacio-Mejía, Christopher Plott, Eugene V. Shakirov, Shengqiang Shu, Yuko Yoshinaga, Matt Zane, Dave Kudrna, Jason D. Talag, Daniel Rokhsar, Jane Grimwood, Jeremy Schmutz, Thomas E. Juenger

Biological Sciences Faculty Research

Environmental stress is a major driver of ecological community dynamics and agricultural productivity. This is especially true for soil water availability, because drought is the greatest abiotic inhibitor of worldwide crop yields. Here, we test the genetic basis of drought responses in the genetic model for C4 perennial grasses, Panicum hallii, through population genomics, field-scale gene-expression (eQTL) analysis, and comparison of two complete genomes. While gene expression networks are dominated by local cis-regulatory elements, we observe three genomic hotspots of unlinked trans-regulatory loci. These regulatory hubs are four times more drought responsive than the genome-wide average. Additionally, cis- and trans-regulatory …


Burned Area Mapping Of An Escaped Fire Into Tropical Dry Forest In Western Madagascar Using Multi-Season Landsat Oli Data, Anne C. Axel Mar 2018

Burned Area Mapping Of An Escaped Fire Into Tropical Dry Forest In Western Madagascar Using Multi-Season Landsat Oli Data, Anne C. Axel

Biological Sciences Faculty Research

A human-induced fire cleared a large area of tropical dry forest near the Ankoatsifaka Research Station at Kirindy Mitea National Park in western Madagascar over several weeks in 2013. Fire is a major factor in the disturbance and loss of global tropical dry forests, yet remotely sensed mapping studies of fire-impacted tropical dry forests lag behind fire research of other forest types. Methods used to map burns in temperature forests may not perform as well in tropical dry forests where it can be difficult to distinguish between multiple-age burn scars and between bare soil and burns. In this study, the …


Genetic Diversity And Differentiation Patterns In Micromeria From The Canary Islands Are Congruent With Multiple Colonization Dynamics And The Establishment Of Species Syngameons, Manuel Curto, Pamela Puppo, S. Kratschmer, H. Meimberg Aug 2017

Genetic Diversity And Differentiation Patterns In Micromeria From The Canary Islands Are Congruent With Multiple Colonization Dynamics And The Establishment Of Species Syngameons, Manuel Curto, Pamela Puppo, S. Kratschmer, H. Meimberg

Biological Sciences Faculty Research

Background

Especially on islands closer to the mainland, such as the Canary Islands, different lineages that originated by multiple colonization events could have merged by hybridization, which then could have promoted radiation events (Herben et al., J Ecol 93: 572–575, 2005; Saunders and Gibson, J Ecol 93: 649–652, 2005; Caujapé-Castells, Jesters, red queens, boomerangs and surfers: a molecular outlook on the diversity of the Canarian endemic flora, 2011). This is an alternative to the scenario where evolution is mostly driven by drift (Silvertown, J Ecol 92: 168–173, 2004; Silvertown et al., J Ecol 93: 653–657, 2005). In the former case …


Redescription Of Euscorpius Tauricus (C.L. Koch, 1837), With The Description Of Two New Related Species From Greece (Scorpiones: Euscorpiidae), Gioele Tropea, Victor Fet, Aristeidis Parmakelis, Panayiota Kotsakiozi, Iasmi Stathi Jan 2017

Redescription Of Euscorpius Tauricus (C.L. Koch, 1837), With The Description Of Two New Related Species From Greece (Scorpiones: Euscorpiidae), Gioele Tropea, Victor Fet, Aristeidis Parmakelis, Panayiota Kotsakiozi, Iasmi Stathi

Biological Sciences Faculty Research

Euscorpius tauricus (C. L. Koch, 1837) was previously known only from the Crimea Peninsula, Ukraine. We report an unexpected presence of this species in the Cyclades Islands (Greece) and northwestern Anatolia (Turkey). In addition we designate a neotype for this species. We synonymize Euscorpius carpathicus aegaeus Di Caporiacco, 1950 syn. n., from Antiparos Island and Euscorpius rahsenae Yağmur et Tropea, 2013 syn. n., from Anatolia, with E. tauricus. In addition, we describe two new species related to E. tauricus, from the Cyclades Islands: E. curcici sp. n., from Ios and Sikinos Islands, and E. amorgensis sp. n., from Amorgos Island. …


Drought Responsive Gene Expression Regulatory Divergence Between Upland And Lowland Ecotypes Of A Perennial C4 Grass, John T. Lovell, Scott Schwartz, David B. Lowry, Eugene V. Shakirov, Jason E. Bonnette, Xiaoyu Weng, Mei Wang, Jenifer Johnson, Avinash Sreedasyam, Christopher Plott, Jerry Jenkins, Jeremy Schmutz, Thomas E. Juenger Mar 2016

Drought Responsive Gene Expression Regulatory Divergence Between Upland And Lowland Ecotypes Of A Perennial C4 Grass, John T. Lovell, Scott Schwartz, David B. Lowry, Eugene V. Shakirov, Jason E. Bonnette, Xiaoyu Weng, Mei Wang, Jenifer Johnson, Avinash Sreedasyam, Christopher Plott, Jerry Jenkins, Jeremy Schmutz, Thomas E. Juenger

Biological Sciences Faculty Research

Climatic adaptation is an example of a genotype-by-environment interaction (G×E) of fitness. Selection upon gene expression regulatory variation can contribute to adaptive phenotypic diversity; however, surprisingly few studies have examined how genome-wide patterns of gene expression G×E are manifested in response to environmental stress and other selective agents that cause climatic adaptation. Here, we characterize drought-responsive expression divergence between upland (drought-adapted) and lowland (mesic) ecotypes of the perennial C4 grass, Panicum hallii, in natural field conditions. Overall, we find that cis-regulatory elements contributed to gene expression divergence across 47% of genes, 7.2% of which exhibit drought-responsive G×E. …


Genetic Structure Of Micromeria (Lamiaceae) In Tenerife, The Imprint Of Geological History And Hybridization On Within-Island Diversification, Pamela Puppo, Manuel Curto, Harald Meimberg Mar 2016

Genetic Structure Of Micromeria (Lamiaceae) In Tenerife, The Imprint Of Geological History And Hybridization On Within-Island Diversification, Pamela Puppo, Manuel Curto, Harald Meimberg

Biological Sciences Faculty Research

Geological history of oceanic islands can have a profound effect on the evolutionary history of insular flora, especially in complex islands such as Tenerife in the Canary Islands. Tenerife results from the secondary connection of three paleo-islands by a central volcano, and other geological events that further shaped it. This geological history has been shown to influence the phylogenetic history of several taxa, including genus Micromeria (Lamiaceae). Screening 15 microsatellite markers in 289 individuals representing the eight species of Micromeria present in Tenerife, this study aims to assess the genetic diversity and structure of these species and its relation with …


A New Species Of Euscorpius (Scorpiones: Euscorpiidae) From Southern Bulgaria, Gioele Tropea, Victor Fet, Aristeidis Parmakelis, Panayiota Kotsakiozi, Iasmi Stathi Jun 2015

A New Species Of Euscorpius (Scorpiones: Euscorpiidae) From Southern Bulgaria, Gioele Tropea, Victor Fet, Aristeidis Parmakelis, Panayiota Kotsakiozi, Iasmi Stathi

Biological Sciences Faculty Research

A new scorpion species, Euscorpius drenskii sp. nov., is described from the Western Rhodope Mts. in southern Bulgaria. It is characterized by an oligotrichous trichobothrial pattern, which shows a conspicuous loss of one trichobothrium in the external median patellar series (em = 3), also observed in E. carpathicus (Linnaeus, 1767) and the subgenus Alpiscorpius Gantenbein, Fet, Largiadèr & Scholl, 1999. Phylogenetic analysis of 16S rDNA marker sequences does not show any close relationship between these three groups, suggesting that the observed loss of a trichobothrium is an independent event.


Two New Species Of Euscorpius From Euboea Island, Greece (Scorpiones: Euscorpiidae), Victor Fet, Michael E. Soleglad, Aristeidis Parmakelis, Panayiota Kotsakiozi, Iasmi Stathi May 2014

Two New Species Of Euscorpius From Euboea Island, Greece (Scorpiones: Euscorpiidae), Victor Fet, Michael E. Soleglad, Aristeidis Parmakelis, Panayiota Kotsakiozi, Iasmi Stathi

Biological Sciences Faculty Research

We describe two new species of the genus Euscorpius from Euboea Island, Greece: E. birulai sp.n. (Agia Triada Cave) and E. mylonasi sp.n. (Mt. Dirfi). The cave species E. birulai sp.n. is morphologically close to E. koschewnikowi Birula, 1900 from Mt. Athos, Greece. Species-level divergence of E. mylonasi sp.n. is also confirmed by multiple DNA markers. According to DNA data, an undescribed population from the nearby Skyros Island is closely related to E. mylonasi sp.n.


A New Species Of Euscorpius From Tinos Island, Greece (Scorpiones: Euscorpiidae), Victor Fet, Michael E. Soleglad, Aristeidis Parmakelis, Panayiota Kotsakiozi, Iasmi Stathi Dec 2013

A New Species Of Euscorpius From Tinos Island, Greece (Scorpiones: Euscorpiidae), Victor Fet, Michael E. Soleglad, Aristeidis Parmakelis, Panayiota Kotsakiozi, Iasmi Stathi

Biological Sciences Faculty Research

The scorpion genus Euscorpius has been insufficiently studied on the Aegean Islands of Greece. We describe a new species from the Western Cyclades, E. kritscheri sp. n., from Tinos Island. The species-level status of this form is confirmed by a phylogenetic study based on multiple DNA markers. In addition, a population from nearby Andros Island is characterized as E. cf. kritscheri, which could be potentially a separate species.


Euscorpius Sicanus (Scorpiones: Euscorpiidae) From Tunisia: Dna Barcoding Confirms Ancient Disjunctions Across The Mediterranean Sea, Matthew R. Graham, Pavel Stoev, Nesrine Akkari, Gergin Blagoev, Victor Fet Sep 2012

Euscorpius Sicanus (Scorpiones: Euscorpiidae) From Tunisia: Dna Barcoding Confirms Ancient Disjunctions Across The Mediterranean Sea, Matthew R. Graham, Pavel Stoev, Nesrine Akkari, Gergin Blagoev, Victor Fet

Biological Sciences Faculty Research

We used a DNA barcoding marker (mitochondrial cox1) to investigate the controversial natural occurrence of Euscorpius sicanus (C.L. Koch) in North Africa. We tested this hypothesis by comparing a sample collected from a mountain in Tunisia to disjunct populations in Sardinia, Malta, and Greece. Using these samples, and a few additional Euscorpius spp. from southern Europe as outgroups, we reconstructed the maternal phylogeny. We then used a molecular clock to place the phylogeny in a temporal context. The Tunisian sample grouped closest to a specimen from Sardinia, with both being more distantly related to E. sicanus from Malta, which is …


Selaginella Moellendorffii Telomeres: Conserved And Unique Features In An Ancient Land Plant Lineage, Eugene V. Shakirov, Dorothy E. Shippen Jul 2012

Selaginella Moellendorffii Telomeres: Conserved And Unique Features In An Ancient Land Plant Lineage, Eugene V. Shakirov, Dorothy E. Shippen

Biological Sciences Faculty Research

Telomeres, the essential terminal regions of linear eukaryotic chromosomes, consist of G-rich DNA repeats bound by a plethora of associated proteins. While the general pathways of telomere maintenance are evolutionarily conserved, individual telomere complex components show remarkable variation between eukaryotic lineages and even within closely related species. The recent genome sequencing of the lycophyte Selaginella moellendorffii and the availability of an ever-increasing number of flowering plant genomes provides a unique opportunity to evaluate the molecular and functional evolution of telomere components from the early evolving non-seed plants to the more developmentally advanced angiosperms. Here we analyzed telomere sequence in S. …


Toward The History Of Study Of Symbiogenesis: On The English Translation Of B. M. Kozo-Polyansky’S A New Principle Of Biology (1924), Victor Fet Jan 2012

Toward The History Of Study Of Symbiogenesis: On The English Translation Of B. M. Kozo-Polyansky’S A New Principle Of Biology (1924), Victor Fet

Biological Sciences Faculty Research

We reproduce the text by Victor Fet, which was read on 6 October 2011 at the Moscow Society of Naturalists during the presentation of new book translation (B.M. Kozo- Polyansky. Symbiogenesis: A New Principle of Evolution / transl. by Victor Fet; ed. by Victor Fet & Lynn Margulis. Cambridge, Mass.: Harvard University Press, 2010. 138 p.) This half- forgotten book by Boris M. Kozo-Polyansky was known only by name to Western biologists. Victor Fet gives a brief history of this new translation, enthusiastically initiated and supported by Lynn Margulis (1938–2011), a famous naturalist who was always eager to gave credit …


A New Skeleton Of The Cryptoclidid Plesiosaur Tatenectes Laramiensis Reveals A Novel Body Shape Among Plesiosaurs, F. Robin O’Keefe, Hallie P. Street, Benjamin C. Wilhelm, Courtney D. Richards, Helen Zhu Jan 2011

A New Skeleton Of The Cryptoclidid Plesiosaur Tatenectes Laramiensis Reveals A Novel Body Shape Among Plesiosaurs, F. Robin O’Keefe, Hallie P. Street, Benjamin C. Wilhelm, Courtney D. Richards, Helen Zhu

Biological Sciences Faculty Research

Current knowledge of plesiosaurs of clade Cryptoclidia is constrained by a lack of fossils from outside the Oxford Clay deposits of England. Recent fieldwork in the Sundance Formation of the Bighorn Basin, Wyoming, has resulted in the recovery of significant new fossils of cryptoclidid plesiosaurs, including the small-bodied form Tatenectes laramiensis. A new partial skeleton of this taxon is reported here; it is the most complete and best-preserved example of the taxon found to date, comprising a complete dorsal vertebral series, many ribs and gastralia, and a complete pelvic girdle. This skeleton illuminates several unique features of the taxon, …


A New Partial Skeleton Of A Cryptocleidoid Plesiosaur From The Upper Jurassic Sundance Formation Of Wyoming, Benjamin C. Wilhelm, F. Robin O’Keefe Dec 2010

A New Partial Skeleton Of A Cryptocleidoid Plesiosaur From The Upper Jurassic Sundance Formation Of Wyoming, Benjamin C. Wilhelm, F. Robin O’Keefe

Biological Sciences Faculty Research

Cryptocleidoid plesiosaurs from the Upper Jurassic are well known from the Oxford Clay (Callovian) of the United Kingdom. The plesiosaurs of the nearly coeval Sundance Formation (Oxfordian) of North America are poorly known, but are thought to include two cryptocleidoid taxa:Pantosaurus striatus and Tatenectes laramiensis. Here we present two specimens recently recovered from the Bighorn Basin of Wyoming. The first specimen comprises three articulated adult cervical vertebrae and fragments of a fourth. This specimen preserves a posteriorly directed cervical neural spine, a character diagnostic of Pantosaurus striatus. It also resembles Pantosaurus in the morphology of its cervical …


Spatial Heterogeneity Of Soil Nutrients And Plant Species In Herb-Dominated Communities Of Contrasting Land Use, Frank S. Gilliam, David A. Dick Jul 2010

Spatial Heterogeneity Of Soil Nutrients And Plant Species In Herb-Dominated Communities Of Contrasting Land Use, Frank S. Gilliam, David A. Dick

Biological Sciences Faculty Research

Recent interest in spatial pattern in terrestrial ecosystems has come from an awareness of theintimate relationship between spatial heterogeneity of soil resources and maintenance of plant species diversity. Soil and vegetation can vary spatially inresponse to several state factors of the system. In this study, we examined fine-scale spatial variability of soil nutrients and vascular plant species in contrasting herb-dominated communities (a pasture and an oldfield) to determine degree of spatial dependenceamong soil variables and plant community characteristics within these communities by sampling at 1-m intervals. Each site was divided into 25 1-m 2 plots. Mineral soil was sampled (2-cm …


Evidence Of Pachyostosis In The Cryptocleidoid Plesiosaur Tatenectes Laramiensis From The Sundance Formation Of Wyoming, Hallie P. Street, F. Robin O’Keefe Jan 2010

Evidence Of Pachyostosis In The Cryptocleidoid Plesiosaur Tatenectes Laramiensis From The Sundance Formation Of Wyoming, Hallie P. Street, F. Robin O’Keefe

Biological Sciences Faculty Research

In this paper we present evidence for pachyostosis in the cryptocleidoid plesiosaur Tatenectes laramiensis Knight, 1900 (O'Keefe and Wahl, 2003a). Pachyostosis is not common in plesiosaurs and is particularly rare in non-pliosaurian plesiosaurs, although enlarged gastralia were first recognized in Tatenectes by Wahl (1999). This study aims to investigate the nature of the disproportionately large gastralia of Tatenectes m greater depth, based on new material. A recently discovered partial skeleton consisting of a dorsal vertebral series, ribs, gastralia, and a complete pelvic girdle was collected from the Jurassic-aged Sundance Formation of the Bighorn Basin in Wyoming during the summer of …


Global Assessment Of Nitrogen Deposition Effects On Terrestrial Plant Diversity : A Synthesis, R. Bobbink, K. Hicks, J. Galloway, T. Spranger, R. Alkemade, M. Ashmore, M. Bustamante, S. Cinderby, E. Davidson, F. Dentener, B. Emmett, J. W. Erisman, M. Fenn, Frank S. Gilliam, A. Nordin, L. Pardo, W. Devries Jan 2010

Global Assessment Of Nitrogen Deposition Effects On Terrestrial Plant Diversity : A Synthesis, R. Bobbink, K. Hicks, J. Galloway, T. Spranger, R. Alkemade, M. Ashmore, M. Bustamante, S. Cinderby, E. Davidson, F. Dentener, B. Emmett, J. W. Erisman, M. Fenn, Frank S. Gilliam, A. Nordin, L. Pardo, W. Devries

Biological Sciences Faculty Research

Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to tropical forests. Current thinking on the mechanisms of N deposition effects on plant diversity, the global distribution of G200 ecoregions, and current and future (2030) estimates of atmospheric N-deposition rates are then used to identify the risks to plant diversity in all major ecosystem types now …


A Plesiosaur Containing An Ichthyosaur Embryo As Stomach Contents From The Sundance Formation Of The Bighorn Basin, Wyoming, F. Robin O’Keefe, Hallie P. Street, Jean Pierre Cavigelli, John J. Socha, R. Dennis O'Keefe Jan 2009

A Plesiosaur Containing An Ichthyosaur Embryo As Stomach Contents From The Sundance Formation Of The Bighorn Basin, Wyoming, F. Robin O’Keefe, Hallie P. Street, Jean Pierre Cavigelli, John J. Socha, R. Dennis O'Keefe

Biological Sciences Faculty Research

Herein we report the discovery of an ichthyosaur embryo from the Upper Member of the Sundance Formation (Oxfordian) of the Bighorn Basin, Wyoming. The specimen is the first known ichthyosaur embryo from the Upper Jurassic, and is the first Jurassic ichthyosaur embryo from North America. The embryo was discovered in close association with the abdomen of an articulated partial plesiosaur skeleton, and several lines of evidence support the interpretation of the embryo as plesiosaur stomach contents. The small size and extremely poor ossification of the embryo indicate that the animal was probably not a neonate. Although the taxonomic affinities of …


Osteology Of The Cryptocleidoid Plesiosaur Tatenectes Laramiensis, With Comments On The Taxonomic Status Of The Cimoliasauridae, F. Robin O’Keefe, Hallie P. Street Jan 2009

Osteology Of The Cryptocleidoid Plesiosaur Tatenectes Laramiensis, With Comments On The Taxonomic Status Of The Cimoliasauridae, F. Robin O’Keefe, Hallie P. Street

Biological Sciences Faculty Research

Recent field work in the Bighorn Basin, Wyoming has recovered significant new material of the plesiosaur Tatenectes laramiensis. The majority of cryptocleidoid plesiosaurs have been recovered from Middle and Upper Jurassic units (Oxford and Kimmeridge Clays, respectively) in the United Kingdom, but Tatenectes laramiensis is one of at least two cryptocleidoids known from the Upper Sundance Member of the Sundance Formation (Oxfordian) of North America. Although poorly known, they bear directly on both the phylogeny and biogeography of the cryptocleidoid plesiosaurs. Here we describe new fossil material of Tatenectes, and reevaluate the phylogenetic position of this genus based on all …


Cranial Anatomy And Taxonomy Of Dolichorhynchops Bonneri New Combination, A Polycotylid (Sauropterygia: Plesiosauria) From The Pierre Shale Of Wyoming And South Dakota, F. Robin O’Keefe Jan 2008

Cranial Anatomy And Taxonomy Of Dolichorhynchops Bonneri New Combination, A Polycotylid (Sauropterygia: Plesiosauria) From The Pierre Shale Of Wyoming And South Dakota, F. Robin O’Keefe

Biological Sciences Faculty Research

The taxonomic identity of two well-preserved polycotylid plesiosaur skeletons from the Pierre Shale of far northern Wyoming and southern South Dakota has been controversial since their discovery. Originally referred to Dolichorhynchops osborni, the material was almost immediately christened Trinacromerum bonneri Adams 1997; more recently the material has been referred toPolycotylus. Recent preparation of the well-preserved skull of one specimen permits detailed examination of the cranial morphology of this animal for the first time, and allows for its inclusion in a cladistic analysis of the Polycotylidae. This analysis reveals a stable sister-taxon relationship with Dolichorhynchops osborni. However, …


Morphologic And Ontogenetic Patterns In Elasmosaur Neck Length, With Comments On The Taxonomic Utility Of Neck Length Variables, F. Robin O’Keefe, Norton Hiller Jun 2006

Morphologic And Ontogenetic Patterns In Elasmosaur Neck Length, With Comments On The Taxonomic Utility Of Neck Length Variables, F. Robin O’Keefe, Norton Hiller

Biological Sciences Faculty Research

Elasmosaur cervical vertebrae are common fossils, but their taxonomic utility is limited due to a lack of understanding concerning their shape within and among taxa. In this paper, we analyze data from complete elasmosaur necks in an attempt to quantify and understand the variation in centrum dimensions. In accord with previous studies, variation in cervical centrum shape is found to stem from at least three sources: ontogeny, intracolumn variation, and intercolumn or taxonomic variation. Ontogenetic variability seems reminiscent of that seen in Cryptoclidus, with an overall positive allometry in the length of all centra that is accentuated in the mid-cervical …


Conservation And Restoration Of The Pinus Palustris Ecosystem, Frank S. Gilliam, William J. Platt May 2006

Conservation And Restoration Of The Pinus Palustris Ecosystem, Frank S. Gilliam, William J. Platt

Biological Sciences Faculty Research

The well-documented decline of the Pinus palustris ecosystem has resulted from several anthropogenic influences, such as forest clearing (e.g. pine plantation forestry, agriculture) and urban development, both of which are closely related to increases in human populations. Other impacts have arisen from alterations in disturbance regimes responsible for maintaining the structure and function of these ecosystems. Restoration and management of degraded pine savanna ecosystems is critical. Identification of ecological processes that determine the structure and function of the intact system are important because successful restoration efforts should be based on sound scientific understanding. In this paper, we introduce this special …


Natural Disturbances And The Physiognomy Of Pine Savannas : A Phenomenological Model, Frank S. Gilliam, William J. Platt, Robert K. Peet May 2006

Natural Disturbances And The Physiognomy Of Pine Savannas : A Phenomenological Model, Frank S. Gilliam, William J. Platt, Robert K. Peet

Biological Sciences Faculty Research

Abstract. Question: The decline of the Pinus palustris ecosystems has resulted from anthropogenic influences, such as conversion to pine plantation forestry, agriculture and land development, all of which are closely related to increases in human populations. Other effects, however, have arisen from alterations in disturbance regimes that maintain the structure and function of these ecosystems. How have alterations of the disturbance regime altered the physiognomy of ‘old-growth’ stands, and what are the implications for ecosystem conservation and restoration?

Methods: In contrast to models that emphasize close interactions among the vertically complex strata, we develop a conceptual phenomenological model for the …


Neoteny And The Plesiomorphic Condition Of The Plesiosaur Basicranium, F. Robin O’Keefe Jan 2006

Neoteny And The Plesiomorphic Condition Of The Plesiosaur Basicranium, F. Robin O’Keefe

Biological Sciences Faculty Research

The purpose of this paper is to describe the condition of the braincase in stratigraphically early and morphologically primitive plesiosaurs. Information on the braincase of plesiomorphic taxa is important because it establishes the polarity of characters occurring in more derived plesiosaurs. This paper begins with a short review of braincase anatomy in stem-group sauropterygians. Data on braincase morphology of the plesiomorphic plesiosaur genera Thalassiodracon and Eurycleidus are then presented and interpreted via comparison with other plesiosaurs, stemgroup sauropterygians, and stem diapsids (Araeoscelis). Early diapsids are relevant because plesiosaur skulls more closely resemble early diapsids than stem-group sauropterygians in several key …


The Vertebrate Fauna Of The Upper Permian Of Niger. Iv. Nigerpeton Ricqlesi (Temnospondyli: Cochleosauridae), And The Edopoid Colonization Of Gondwana, J. Sebastien Steyer, Ross Damiani, Christian A. Sidor, F. Robin O’Keefe, Hans C.E. Larsson, Abdoulaye Maga, Oumarou Ide Jan 2006

The Vertebrate Fauna Of The Upper Permian Of Niger. Iv. Nigerpeton Ricqlesi (Temnospondyli: Cochleosauridae), And The Edopoid Colonization Of Gondwana, J. Sebastien Steyer, Ross Damiani, Christian A. Sidor, F. Robin O’Keefe, Hans C.E. Larsson, Abdoulaye Maga, Oumarou Ide

Biological Sciences Faculty Research

We describe the edopoid temnospondyl Nigerpeton ricqlesi from the Upper Permian Moradi Formation of northern Niger on the basis of two partial skulls and tentatively associated postcranial material. This crocodile-like taxon displays several edopoid characters states such as a long prenarial region with enlarged premaxillae, elongated vomers, large, posteriorly tapering choanae, and a jugal that broadens anteriorly. Nigerpeton possesses a unique carnivorous dentition. It is autapomorphic in its possession of an extremely elongate snout bearing a maxillary bulge that accommodates three hypertrophied caniniform teeth, inner premaxillary tusks, and anterior paired fenestrae, which pierce the skull roof. In addition, both the …


The Vertebrate Fauna Of The Upper Permian Of Niger—Iii, Morphology And Ontogeny Of The Hindlimb Of Moradisaurus Grandis (Reptilia, Captorhinidae), F. Robin O’Keefe, Christian A. Sidor, Hans C. E. Larsson, Abdoulaye Maga, Oumarou Ide Jan 2005

The Vertebrate Fauna Of The Upper Permian Of Niger—Iii, Morphology And Ontogeny Of The Hindlimb Of Moradisaurus Grandis (Reptilia, Captorhinidae), F. Robin O’Keefe, Christian A. Sidor, Hans C. E. Larsson, Abdoulaye Maga, Oumarou Ide

Biological Sciences Faculty Research

We describe hindlimb elements of the large captorhinid Moradisaurus grandis (Reptilia: Captorhinidae) recently collected from the Upper Permian Moradi Formation of north-central Niger. This description is based primarily on an associated partial skeleton comprising a hemimandible, vertebral column, and partial left and nearly complete right hindlimb. Additionally, we report on a well-preserved, articulated, and essentially complete juvenile pes that provides important information on the ontogeny of the captorhinid tarsus. The hindlimb of Moradisaurus is stout and more massively built than in any other known captorhinid. The femur displays several features interpreted as adaptations to the demands of large body size, …


On The Cranial Anatomy Of The Polycotylid Plesiosaurs, Including New Material Of Polycotylus Latipinnis, Cope, From Alabama, F. Robin O’Keefe Jan 2004

On The Cranial Anatomy Of The Polycotylid Plesiosaurs, Including New Material Of Polycotylus Latipinnis, Cope, From Alabama, F. Robin O’Keefe

Biological Sciences Faculty Research

The cranial anatomy of plesiosaurs in the family Polycotylidae (Reptilia: Sauropterygia) has received renewed attention recently because various skull characters are thought to indicate plesiosauroid, rather than pliosauroid, affinities for this family. New data on the cranial anatomy of polycotylid plesiosaurs is presented, and is shown to compare closely to the structure of cryptocleidoid plesiosaurs. The morphology of known polycotylid taxa is reported and discussed, and a preliminary phylogenetic analysis is used to establish ingroup relationships of the Cryptocleidoidea. This study also presents new material referable to Polycotylus latipinnis from the Mooreville Chalk Formation of Alabama. This skeleton is largely …