New Cladid Crinoid (Phylum Echinodermata) from the Middle Devonian Delaware Limeston, Franklin County, Ohio

Author Institution: Department of Geological Sciences, The Ohio State UniversityA new species of Goniocrinus, G. saettii, is described from the Delaware Limestone of Franklin County, OH. This is the first crinoid described from the Delaware Limestone and the first cladid crinoid described from Devonian limestones of Ohio. This new occurrence suggests that additional new echinoderm specimens may be found in Devonian limestones of Ohio with a directed search for strata conducive to complete echinoderm preservation, that is, rapidly deposited, fine-grained facies

Biovolume Revisited: A Relative Diversity Index for Paleological Analyses

Author Institution: Wright State UniversityA new application of the biovolume abundance index is proposed for relative diversity demography in paleoecological analyses. Use of this technique will improve confidence in data validity and solve the following inadequacies of other numerical census techniques: all groups are treated equally, samples from different lithologies can be meaningfully compared, colonial and solitary organisms are treated equally, whole and fragmentary fossils are treated equally, and time averaging effects are assumed. Biovolume is the paleontological analog of biomass, and it is a measure of the relative amount of energy expended by organisms to secrete skeletal material that has been incorporated into the rock record

BIOMARKERS IN PALEOZOIC CRINOIDS (BORDEN GROUP, MISSISSIPPIAN): IMPLICATIONS FOR PHYLOGENY

O'Malley, Christina E., Ausich, William I., and Chin, Yu Ping 2005, Biomarkers in Paleozoic crinoids (Borden Group, Mississippian): implications for Phylogeny [poster]: Geological Society of America Annual Meeting, 2005, Session 57, Paper 57-8. Abstract published: Geological Society of America, Abstracts with Programs, Vol. 37, No. 7, p. 133; http://gsa.confex.com/gsa/2005AM/finalprogram/abstract_95335.ht

Treatise on Invertebrate Paleontology

This volume is edited by Paul Selden, authors are Hans Hess and Charles G. Messing, coordinating author is William I. Ausich. This is the first volume to be published in an extensive revision of the Class Crinoidea. The present volume deals with the Subclass Articulata that contains all post-Paleozoic and living crinoids. The descriptions are preceded by an introduction, a chapter on the morphology of articulate crinoids, a glossary of important terms, and an overview of classification. The reference list is comprehensive for this volume.https://nsuworks.nova.edu/occ_facbooks/1009/thumbnail.jp

Taphonomy of Isocrinid Stalks: Influence of Decay and Autotomy

Stalks of isocrinid crinoids are differentiated into cirri-bearing columnals (nodals) and columnals lacking cirri (internodals). This skeletal differentiation allowed us to test whether stalk fragmentation is random or whether it occurs preferentially at a specific articulation. Our analyses indicate that the patterns of fragmentation in multicolumnal segments of extant isocrinids collected by submersible, by dredging, and in sediment samples, as well as those found as fossils, are nonrandom. The preferred plane of fragmentation corresponds to the synostosis, the articulation between a nodal and the internodal distal to it. In isocrinids this articulation has a characteristic morphology and is the site of autotomy. Although stalk shedding by autotomy may contribute to the observed patterns, decay experiments on isocrinid stalks, both in situ and in the lab, suggest that post-mortem disarticulation also results in nonrandom fragmentation. Thus both processes, autotomy and post-mortem decay, contribute to the observed pattern of fragmentation. Underlying both processes is the organization of soft tissues at synostoses

Stars in the Silurian sky: Echinoderm holdfasts from the Carnic Alps

A small collection of echinoderm holdfasts from the Ludlow Cardiola Formation of the Carnic Alps (Austria) contains a wide range of morphologies as a response of environmental adaptation. In general, the holdfasts have a globous and massive dome-like profile with several processes arranged in a sub-radial disposition, so to create a sort of ‘star-like’ outline. A small central depression is common but not present on all specimens. The distinctive holdfasts are preserved in an iron-rich phase, documenting a substitution that has also affected other non-echinoderm calcareous material

Stars in the Silurian sky : Echinoderm holdfasts from the Carnic Alps, Austria

A small collection of echinoderm holdfasts from the Ludlow Cardiola Formation of the Carnic Alps (Austria) contains a wide range of morphologies as a response of environmental adaptation. In general, the holdfasts have a globous and massive dome-like profile with several processes arranged in a sub-radial disposition, so to create a sort of 'star-like' outline. A small central depression is common but not present on all specimens. The distinctive holdfasts are preserved in an iron-rich phase, documenting a substitution that has also affected other non-echinoderm calcareous material

Phylogeny of Arenig to Caradoc crinoids (Phylum Echinodermata) and suprageneric classification of the Crinoidea

36 p., 11 fig., 3 tables.http://paleo.ku.edu/contributions.htm

Functional diversity of marine ecosystems after the Late Permian mass extinction event

Article can be accessed from http://www.nature.com/ngeo/journal/v7/n3/full/ngeo2079.htmlThe Late Permian mass extinction event was the most severe such crisis of the past 500 million years and occurred during an episode of global warming. It is assumed to have had significant ecological impact, but its effects on marine ecosystem functioning are unknown and the patterns of marine recovery are debated. We analysed the fossil occurrences of all known Permian-Triassic benthic marine genera and assigned each to a functional group based on their inferred life habit. We show that despite the selective extinction of 62-74% of marine genera there was no significant loss of functional diversity at the global scale, and only one novel mode of life originated in the extinction aftermath. Early Triassic marine ecosystems were not as ecologically depauperate as widely assumed, which explains the absence of a Cambrian-style Triassic radiation in higher taxa. Functional diversity was, however, significantly reduced in particular regions and habitats, such as tropical reefs, and at these scales recovery varied spatially and temporally, probably driven by migration of surviving groups. Marine ecosystems did not return to their pre-extinction state, however, and radiation of previously subordinate groups such as motile, epifaunal grazers led to greater functional evenness by the Middle Triassic