No description available.

Pterotocrinus is an echinoderm of the class Crinoidea that is restricted to the Chesterian Series (Chestnut and Ettensohn, 1988; Sutton, 1934). The most identifiable and best preserved remains of Pterotocrinus are the wing plates (Welsh, 1978). These wing plates are specialized tegmen plates that give Pterotocrinus its name (from pteron, Greek for "wing") (Welsh, 1978). This study questions whether or not wing plates can be used for biostratigraphy throughout the Chesterian Series, as well as what the functions of the wing plates were. New morphologies of Pterotocrinus found within the Menard Limestone during this study bring into question the biostratigraphical usefulness of many of the morphologies of Pterotocrinus wing plates. Certain species of Pterotocrinus appear to remain valuable index fossils within the Menard Limestone and the Kinkaid Formation. Four new morphologies were collected within the Menard Limestone during this study. These new finds draw questions about our knowledge of this genus. This study also attempted to explain the function of the wing plate, and how it may have changed over time. Pterotocrinus wing plates evolved rapidly during the Chesterian Series developing vastly different morphologies from the time the Menard Limestone was deposited to the time when the Kinkaid Formation was deposited. This study suggests a functional shift over time, with the wing plates of the Menard Limestone acting as rudders to orient the calyx to either assist in feeding or reduce stress on the calyx, and the wing plates of the Kinkaid Formation acting as an antipredatory defense mechanism. This study presents new conclusions and new questions regarding the wing plates of Pterotocrinus.

No description available.

No description available.

Book Summary: The state of Tennessee is widely recognized as a home of great music, and its geographic regions are as distinct as Memphis blues, Nashville country, and Bristol old-time sounds. Tennessee’s literary heritage offers equal variety and quality, as home to the Fugitive Agrarian Poets, as well as a signature voice from the Black Arts Movement. Few states present such a multicultural panorama as does the Volunteer State.The poems in The Southern Poetry Anthology, Volume VI: Tennessee engage the storied histories, diverse cultures, and vibrant rural and urban landscapes of the region. Among the more than 120 poets represented are Pulitzer and Bollingen Prize-winner Charles Wright, Brittingham Award-winner Lynn Powell, and Agnes Lynch Starrett Prize-winners Rick Hilles and Arthur Smith.The book includes an introduction from renowned poet Jeff Daniel Marion, who in 1978 received the first literary fellowship from the Tennessee Arts Commission. Too, the book celebrates relatively young and gifted voices. This important anthology will stand for many years as the definitive poetic document for the state of Tennessee.Conceived by Series Editor William Wright in 2003, The Southern Poetry Anthology is a multivolume project celebrating established and emerging poets of the American South. Inspired by single-volume anthologies such as Leon Stokesbury’s The Made Thing, Gil Allen’s A Ninety-Six Sampler, and Guy Owen and Mary C. Williams’ Contemporary Southern Poetry: an Anthology, The Southern Poetry Anthology aspires to provide readers with a documentary-like survey of the best poetry being written in the American South at the present moment.Published exclusively by Texas Review Press, the series provides the most comprehensive representation of Southern poets currently available and is currently being used in university classrooms across the South.

Antedonidae (Crinoidea: Comatulida) is the largest of extant crinoid families; it currently includes ~155 accepted species in 50 genera and accounts for ~23% of extant crinoid species (~29% of feather stars) and 27% of genera. Molecular phylogenies have returned the family as polyphyletic, with several clades scattered among non-antedonid sister groups (Hemery 2011, Hemery et al. 2013, Rouse et al. in prep.). Traditional morphological characteristics are thus inadequate for reconstructing relationships among taxa. SEM imaging was used in an effort to discover new diagnostic features that will support the molecular data, focusing on skeletal ossicles within the calyx, specifically the radial ossicles, as they are least likely to be affected by their hydrodynamic environment. Geometric morphometric analysis and landmark software were used to systematically compare equivalent skeletal parts among antedonid and non-antedonid sister taxa to identify likely homologies and homoplasies. Principal Component Analysis (PCA/BGPCA) and Procrustes ANOVAs were used for visualizing and testing variances within and between taxonomic and molecular groups. Linear Discriminant Analysis (LDA) was used with leave-one-out cross validation (LOOCV) to identify any misclassifications based on morphological similarities. UPGMA Hierarchical clustering models using both Procrustes and Mahalanobis distances were produced for comparison, and inter-landmark measurements were compared between species in search for possible intra-radial character states. Results yielded significant variation of radial morphology within the family Antedonidae with significant effects by depth range, taxonomic classification, and phylogenetic forces. All species with a radial height to width (H:W) ratio <1.0 were restricted to the shallower depths (0-200m) and notable morphological similarities were seen within both molecular clades and taxonomic subfamilies (Antedoninae and Thysanometrinae excepted). Regional affects were seen within the subfamily Antedoninae, as the Atlantic antedonines differed significantly from the Pacific antedonines, both in overall radial appearance and in H:W ratio. These results, with limited variation within molecular clades, give at least rudimentary support to recent molecular phylogenetics and promote further morphological studies of this nature that will strengthen our understanding of extant crinoid phylogeny (Bull et al. 1993, Littlewood et al. 1997, Hemery 2011, Rouse et al. 2013, Roux et al. 2013).

The morphology of members of the isocrinid genus, Endoxocrinus, found by A.H. Clark, 1908, in the Bahamas was examined to see if current classification schemes are valid. Individuals included in this survey belonged to the current species Endoxocrinus prionodes, Endoxocrinus carolinae, and Endoxocrinus parrae. Additionally, individuals of two depth-related morphotypes of E. parrae were examined. Evidence is presented that suggests that E. carolinae should be included in E. parrae, while the validity of E. prionodes is maintained. No evidence was found to warrant the recognition of the two depth-related morphotypes as distinct. Rather, these forms, as well as traditional E. parrae and E. carolinae, encompassed a high degree of variability along a morphological continuum. The study concludes that a revision of the genus should be considered and that isocrinid species can be much more variable in morphology than was previously recognized.

Feather star (Echinodermata: Crinoidea: Comatulida) family Charitometridae has not been revised since 1950. Molecular analysis, new specimens of existing species, and the discovery of a new species has revealed the need for a generic-level revision of those genera that exhibit abruptly expanded genital pinnules. A morphological study was conducted using 57 specimens representing 10 species of the Charitometridae. The genus Poecilometra is redescribed, and two species formerly placed in Strotometra have been moved to the genus based primarily on possession of pedunculate genital pinnules and a wide flange on the first pinnular of the proximal pinnules. A new species was described: Poecilometra tibicinem n. sp. The genus Strotometra is redescribed based on its cirri and laterally expanded genital pinnulars and its extant two species synonymized under Strotometra parvipinna. An undescribed stereomic structure was discovered on the proximal brachial articulations in the medial angles of the muscular fossae in some specimens, but its taxonomic significance remains unresolved.

Crinoids are the most primitive living members of the Phylum Echinodermata. Though still present in reduced numbers today, crinoids were the dominant echinoderms from the Ordovician to the Permian. The crinoid body plan consists of three major regions, the column, the calyx, and the arms. Each region serves important functions in crinoids. The column raises the rest of the body into the water column for more efficient feeding. The calyx contains the visceral mass and mouth. Arms extend out from the top of the calyx to trap microorgansisms and suspended organic particles in the water column. A re-evaluation of these functional units is undertaken to understand the importance of various structures and to obtain discrete characters for use in a cladistic analysis. The relationship of crinoid crown groups has been an active area of research for the past couple of decades. With each proposed phylogenetic relationship, a new interpretation of thecal plate homology has been proposed. Here each study is re-examined in the light of new data. A review of functional morphology indicates a dual-reference system to be the most supported interpretation of plate homology. The two reference points in this system are the stem-cup and the cup-arm junctions, at the top and bottom of the calyx. The difference between a two-circlet and three-circlet crinoid is the presence or absence of the middle (basal) circlet. A new cladistic analysis is presented, with the topology of trees obtained giving support for the retention of Paleozoic crinoid stem and crown groups. Crinoids appear abruptly in the fossil record. Questions pertaining to origins and ancestral stock abound. A biogeography study is employed to look at the distribution of crinoids from the Early to Middle Ordovician. Locality information, combined with an understanding of the movement of major plates, paleoclimate data, an understanding of larval distribution, and a review of similar studies carried out on different taxa, gives insight into possible radiation and dispersal patterns of crinoids from the first half of the Ordovician. / text

Les crinoïdes sont bien connus pour leurs fossiles, mais la biominéralisation de leurs stades larvaires n’est que peu documentée. La première partie du projet présente le développement des ossicules des trois stades larvaires du comatule Florometra serratissima : doliolaria, cystidienne et pentacrinoïde. Les ossicules du crinoïde démontraient de la plasticité phénotypique et de la désynchronisation dans leur développement. Les crinoïdes étant la classe basale des échinodermes modernes, ceci porte à croire que ces traits étaient aussi caractéristiques des échinodermes ancestraux et auraient joué un rôle dans la radiation hâtive et la grande disparité des échinodermes. Pour notre deuxième étude, comme les patrons de morphologie des crinoïdes et des autres échinodermes sont nombreux et sont régulés par des protéines spécifiques, nous avons vérifié la présence de quatre familles de protéines de la matrice de spicules (SMAP) connues chez les oursins dans les transcriptomes des autres échinodermes et d’autres deutérostomes. La famille des spicules matrix (SM) et l’anhydrase carbonique CARA7LA étaient absentes chez tout autre organisme que les oursins, les protéines spécifiques au mésenchyme (MSP130) étaient présentes en nombres différents chez tous les ambulacraires suggérant de multiples duplications et pertes, et les métalloprotéases étaient nombreuses chez chacun. Le développement des ossicules chez les échinodermes est un sujet qui a gagné en popularité au cours des dernières décennies, spécialement chez les oursins, et inclure les crinoïdes dans ce type d’étude permettra de nous renseigner sur l’origine et l’évolution des échinodermes modernes. / While the fossil record of crinoids is widespread and largely known, biomineralization of their larval stages is poorly documented. The first part of the project focuses on the ossicle development of the three larval stages of the feather star Florometra serratissima: doliolaria, cystidean and pentacrinoid. The ossicles of the crinoid showed phenotypic plasticity and asynchronous development. Crinoids form the basal class of living echinoderms; this prompts one to believe that these traits were also characteristic of the ancestral echinoderms and would have played a role in the early radiation and large disparity of the modern echinoderms. For the second study, as patterns of morphology of crinoids and of other echinoderms are numerous and are regulated by specific proteins, we verified the presence of four families of spicule matrix associated proteins (SMAPs) known among sea urchins in transcriptomes of the other echinoderms and deuterostomes. The family of spicule matrix (SMs) proteins and the carbonic anhydrase CARA7LA were absent in any other organism aside from sea urchins, mesenchyme specific proteins (MSP130s) were present in varying numbers in all ambulacrarians suggesting multiple duplications and losses and matrix metalloproteases were numerous in every organisms. The development of ossicles in echinoderms is a topic that has gained popularity in the last decades, especially in sea urchins, and including crinoids in this type of study will inform us about the origin and evolution of the modern echinoderms.