Colin D. Sumrall

Colin D. Sumrall
University of Tennessee | UTK · Department of Earth and Planetary Sciences

PhD

About

166
Publications
31,097
Reads
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1,716
Citations
Additional affiliations
January 1998 - May 2002
Cincinnati Museum Center
Cincinnati Museum Center
Position
  • Curator of Invertebrate Paleontology
Education
January 1990 - May 1996
University of Texas at Austin
Field of study
  • Geological Sciences

Publications

Publications (166)
Article
Full-text available
ABSTRACT—Universal elemental homology (UEH) is used to establish homology of thecal plates and elements of the ambulacral system among clades of stemmed echinoderms by placing these structures into a testable hypothesis of homology. Here UEH is used to explore hypotheses of homology in blastoids, coronoids, Lysocystites, hemicosmitoids, and glyptoc...
Article
Full-text available
A new genus and species of edrioasteroid grade echinoderm, Kailidiscus chinensis, is described from the Kaili Biota of the basal lower Middle Cambrian Kaili Formation from Guizhou Province, China. This echinoderm has a strong resemblance to isorophid edrioasteroids, bearing a well-developed peripheral rim, long curved ambulacra, and slightly imbric...
Article
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A new edrioasteroid fauna from the Ordovician of Morocco, North Africa includes eight new isorophid species placed in six genera of which three are new. A phylogenetic analysis of Moroccan genera and other taxa places these new edrioasteroids into a phylogenetic framework. Pyrgocystidae is redefined to include plesiomorphic isorophids with hood pla...
Article
Extinction of species, and even clades, is a normal part of the macroevolutionary process. However, several times in Earth history the rate of species and clade extinctions increased dramatically compared to the observed “background” extinction rate. Such episodes are global, short-lived, and associated with substantial environmental changes, espec...
Article
Echinoderms are characterized by a distinctive high-magnesium calcite endoskeleton as adults, but elements of this have been drastically reduced in some groups. Herein, we describe a new pentaradial echinoderm, Yorkicystis haefneri n. gen. n. sp., which provides, to our knowledge, the oldest evidence of secondary non-mineralization of the echinoder...
Article
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Origins of higher taxonomic groups entail dramatic and nearly simultaneous changes in morphology and ecological function, limiting our ability to disentangle the drivers of evolutionary diversification. Here we phylogenetically compare the anatomy and life habits of Cambrian–Ordovician echinoderms to test which facet better facilitates future succe...
Conference Paper
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Brittle stars, echinoderms with a large central disk and long, slender arms, are the most species rich class of modern echinoderms. However, our current understanding of brittle star diversity during the Paleozoic presently does not show a similar pattern. Until recently, the known record of this group has been limited because of outdated study met...
Article
Quantifying morphological evolution is key to determining the patterns and processes underlying the origin of phyla. We constructed a hierarchical morphological character matrix to characterize the radiation and establishment of echinoderm body plans during the early Paleozoic. This showed that subphylum-level clades diverged gradually through the...
Article
Communities of organisms that encrusted hardgrounds and skeletal material developed and became widespread during the Great Ordovician Biodiversification Event, and this community structure was a well-established part of the marine ecosystem by the Late Ordovician. Here we describe and investigate an example of skeletal encrustation from the Bardsto...
Conference Paper
Full-text available
Paleozoic brittle star biodiversity is both poorly documented and poorly understood. Brittle stars are echinoderms that easily disarticulate into many individual skeletal elements. Previous studies of Paleozoic brittle stars have relied heavily on fully articulated skeletons which are biased to those faunas, environments, and taxa with excellent pr...
Conference Paper
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The echinoderm group, Ophiuroidea, has a long fossil history but still remains largely understudied especially in the Paleozoic. Most of the documentationhas been through the identification of fully articulated specimens that show the gross overall morphology, but the detailed anatomy of the isolated skeletal elements as has been the primary focus...
Article
Eublastoids are a large clade of blastoids; stemmed blastozoan echinoderms diagnosed by their conservative body plan (three basals, four deltoid plates and five radial plates), lancet plate supporting the ambulacra, and hydrospire respiratory structures. Although Eublastoidea was a highly successful clade in the middle and late Palaeozoic it is abs...
Presentation
Paleozoic ophiuroid biodiversity is poorly documented and taphonomically biased. Previous identification has relied heavily on the study of fully articulated skeletons, limiting our knowledge of individual ossicle morphology and taxonomy. Utilizing techniques common in studies of Mesozoic and Cenozoic taxa has shown surprisingly high generic divers...
Conference Paper
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Paleozoic ophiuroid biodiversity is poorly documented globally. Here, we describe the ophiuroid fauna from the Upper Mississippian (Chesterian) Sulphur, IN locality of the Indian Springs Shale Mb. of the Big Clifty Fm. based on disarticulated ossicles picked from fine-grained shale washings. In the past, Paleozoic ophiuroid taxa were described usin...
Article
Edrioasteroids are an extinct clade of echinoderm that are rarely preserved in the fossil record due to rapid post-mortem disarticulation of their multi-element skeletons. Here we investigate two well-preserved limestone slabs from the Mississippian (Chesterian) Kinkaid Formation of southern Illinois bearing 242 specimens of the edrioasteroid Neois...
Article
The phylogenetic relationships of Paleozoic blastozoan echinoderms are poorly understood and many of the traditionally ascribed groups are likely polyphyletic. Diploporitans, those blastozoans with double pore (diplopore) respiratory structures, have never been placed within a rigorous phylogenetic framework, and their highly variable morphologies...
Article
Recent debates over the evolutionary relationships of early echinoderms have relied heavily on morphological evidence from the feeding ambulacral system. Eumorphocystis, a Late Ordovician diploporitan, has been a focus in these debates because it bears ambulacral features that show strong morphological similarity to early crinoid arms. Undescribed...
Conference Paper
Ordovician echinoderms from central Tennessee are relatively poorly known compared to adjacent strata of the Cincinnati Arch. New species of Ordovician echinoderms from this region are seldom reported, with the exception of the Lebanon Limestone fauna, even though these rocks are well exposed throughout the central basin. Here we report on a new sp...
Article
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Hirnantian (latest Ordovician) localities containing echinoderm fossils are rare; the few that have been discovered primarily contain disarticulated crinoid ossicles. Therefore, relatively little is known about echinoderm evolutionary dynamics across the Late Ordovician – early Silurian boundary, especially noncrinoid echinoderms. New diploporitan...
Article
The external expression of hydrospires in blastoids has provided a basis for major and minor group classification in the clade for over a century. Unfortunately, the complete anatomy of the hydrospires has never been comprehensively studied. This study examined and described the internal hydrospires of six spiraculate species by digitally extractin...
Article
Hydrospires are internal structures in blastoids that primarily served a respiratory function. Historically, hydrospires have been modeled as passive-flow respiratory structures with a vertical orientation. This project constructed virtual 3D models of blastoids from legacy acetate peel collections at the Naturalis Museum in the Netherlands. Comput...
Article
The Furongian (late Cambrian) is an extremely poorly sampled time in the history of echinoderms, with only few localities yielding complete specimens. Here, we document an exquisitely preserved stemmed echinoderm from the Furongian Sandu Formation in South China that provides important new data illuminating the origin of Glyptocystitida, a common P...
Article
The Holocystites Fauna is an enigmatic group of North American diploporitans that presents a rare window into unusual middle Silurian echinoderm communities. Multiple systematic revisions have subdivided holocystitids on the basis of presumed differences in oral area plating and respiratory structures. However, these differences were based on a fun...
Conference Paper
Edrioasteroids are important components of Paleozoic marine communities that, as obligate encrusters, cement themselves to hardgrounds, lithified clasts, and biotic hard substrates. A hardground encrusted by edrioasteroids, when subjected to rapid burial, presents a time-poor, in situ “snapshot” of an ancient assemblage that allows ecological study...
Article
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One important and sometimes contentious challenge in paleobiology is discriminating between species, which is increasingly accomplished by comparing specimen shape. While lengths and proportions are needed to achieve this task, finer geometric information, such as concavity, convexity, and curvature, plays a crucial role in the undertaking. Nonethe...
Conference Paper
In order to better understand diversity and extinction patterns of the spatangoid echinoid clade Mecaster, and to place the clade into a robust paleobiogeographic context, its relationships with major groups need to be better resolved and species level synonymies worked out. Furthermore, data recently collected from Latin America needs to be placed...
Conference Paper
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However, new data from an Upper Ordovician (Hirnantian) fauna from reefal facies of the Ellis Bay Formation collected on Anticosti Island (Quebec, Canada) has expanded our understanding of the phylogenetic, temporal, and biogeographic patterns of the Holocystites Fauna. A previously undescribed holocystitid taxon, Holocystites n. sp., was recently...
Conference Paper
Reevaluation of the type specimens provides evidence that M. uniplicatus is lacking several distinct blastoid characteristics. Macurdablastus uniplicatus possesses the conservative peristomal plating configuration similar to other derived blastozoans (e.g., rhombiferans, parablastoids, blastoids, coronoids, Lysocystites). The lancet plate of M. uni...
Conference Paper
Evolutionary relationships of early echinoderms are poorly understood, largely because of a misunderstanding of homologous skeletal elements. New data from undescribed specimens of Eumorphocystis multiporata, a Middle-Late Ordovician diploporitan from the Bromide Formation of Oklahoma, provides insight into the phylogenetic relationships of blastoz...
Article
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Inferring the development of the earliest echinoderms is critical to uncovering the evolutionary assembly of the phylum-level body plan but has long proven problematic because early ontogenetic stages are rarely preserved as fossils. Here, we use synchrotron tomography to describe a new early post-metamorphic blastoid echinoderm from the Carbonifer...
Article
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Llanocystis wilbernsensis n. gen. n. sp. (Eocrinoidea, Echinodermata) is described based on three specimens from the Furongian Point Peak Shale Member of the Wilberns Formation in central Texas. It displays a unique morphology including a very long stem constructed with holomeric columnals, few feeding appendages, and a poly-plated theca. The speci...
Article
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An unusual, new, giant edrioasteroid Bizarroglobus medusae n. gen. n. sp. is described from the Middle Ordovician Kanosh Shale of west-central Utah. This species has a pattern of ambulacral branching with side ambulacra arising alternately from a main ambulacral trunk, previously undocumented in edrioasteroids. This pattern is interpreted as a stra...
Article
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A new eocrinoid ? Ubaghsicystis sp. from the middle Cambrian (Series 3, Stage 5) Burgess Shale is reported based on a single known specimen. This species extends the stratigraphic range of columnal-bearing eocrinoids in Laurentia significantly from Cambrian Stage 7 (Guzhangian) to Stage 5. It increases the diversity of echinoderms in this well-know...
Article
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The new edrioasterine Pseudedriophus guensburgi n. gen. n. sp., is described from the Lower Ordovician Ninemile Shale of central Nevada based on three complete to partial small specimens, a well-preserved large ambulacrum, and an isolated ambulacral floor plate. The weathered-out holotype of this edrioasterine exposes the bottom surface of the thec...
Conference Paper
Cyclocystoids are a clade of discoidal echinoderms with a well-developed marginal ring and multiply branched ambulacra that were uncommon components of Lower and Middle Paleozoic faunas. Cyclocystoids were rare by the Frasnian (Late Devonian), and none are described from rocks younger the Frasnian/Famennian Mass Extinction. Here we report on two sp...