Geol G308 Paleontology and Geology of Indiana 7 - Crinoids.pdfClass Crinoidea Subclass Inadunata...
Transcript of Geol G308 Paleontology and Geology of Indiana 7 - Crinoids.pdfClass Crinoidea Subclass Inadunata...
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Geol G308
Paleontology and Geology of Indiana
Department of Geological Sciences | P. David Polly 1
Name: _____________________________________
Lab 7 Crinoids
Echinodermata
Phylum Echinodermata
Subphylum Eleutherozoa unstalked echinoderms
Class Holothuroidea – sea cucumbers (Cambrian to Recent) Class Edrioasteroidea – extinct urchin-like echinoderms (Cambrian to Pennsylvanian) Class Helicoplacoidea – extinct mound-like echinoderms (Cambrian) Class Echinoidea – sea urchins (Ordovician to Recent) Class Asteroidea – starfish (Ordovician to Recent) Class Ophiuroidea – brittle stars (Ordovician to Recent)
Subphylum Pelmatozoa stalked echinoderms
Class Paracrinoidea – extinct crinoid-like echinoderms (Ordovician to Silurian) Class Crinoidea – sea lillies (Cambrian to Recent) Class Blastozoa – Blastoids (Silurian to Permian)
Class Blastozoa Blastoids
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Crinoid anatomy
Crinoid anatomy. (Brusca and Brusca, 2003. The Invertebrates. Sinaeur.)
Crinoid skeleton parts.
Cyathocrinites multibrachiatus
Hess et al., 1999. Fossil Crinoids. Cambridge University Press.
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Crinoid columnals (stalk segments). (Hess et al., 1999. Fossil Crinoids. Cambridge University Press.)
Crinoid brachials (arm segements). (Hess et al., 1999. Fossil Crinoids. Cambridge University Press.)
a. Synostosis b. Symplexy c. Synarthry
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Class Crinoidea
Subclass Inadunata Loose or tightly fused plates, poorly developed “camera”, one or two rings of basals
Order Disparida – Inadunates with one ring of basals Order Cladida – Inadunates with two rings of basals
Subclass Camerata Tightly fused calyx plates, “camera” of oral and anal plates, one or two rings of basals
Order Monobathrida – Camerates with one ring of basals Order Diplobathrida – Camerates with two rings of basals
Subclass Flexibi l ia Cladid-like crinoids with infrabasals reduced to three, loosely fused plates, uniserial arms and often flanges on their brachials
Subclass Art iculata Cladid-like crinoids from Triassic to recent
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Cromyocrinus simplex
Cladida, Poteriocrinina
Upper Carboniferous, Russia
Inadunata, Cladida Few or no oral plates, two rings of basals below radials, poorly developed calyx
(radials colored black, orals and anals shaded
Actinocrinites triacontadactylus
Camerata, Monobathrida, Glyptocrinina Middle Ordovician, USA
Camerata , Monobathrida Lots of oral plates, one ring of basals below the radials
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Rhodocrinites kirbyi
Camerata, Diplobathrida, Eudiplobathrida
Mississippian (Burlington Limestone), Iowa
Camerata , Diplobathrida Lots of oral plates, two rings of basals below the radials
(radials colored black, orals and anals shaded
Onychocrinus exsculptus Flexibilia Mississippian, Indiana
Flexibilia Oral plates, two rings of basals below the radials, brachials with flanges at proximal end (radials colored black, orals and anals shaded
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Department of Geological Sciences | P. David Polly 7
Assignment
1. Isolated skeletal elements. For each specimen, indicate whether it is a columnal segment, a brachial segment, or part of a calyx.
Specimen 1: Specimen 2: Specimen 3: Specimen 4: Specimen 5:
2. Identify taxa to Order based on calyx and arm features.
Taxon Oral plates present?
Number of basal rings?
Brachial flanges?
Order
Agaracocrinites
Macrocrinus
Eucalyptocrinus
Glyptocrinus
Crinoid A
Crinoid B
Crinoid C
Crinoid D