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

Department of Geological Sciences | P. David Polly 2

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.

Department of Geological Sciences | P. David Polly 3

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

Department of Geological Sciences | P. David Polly 4

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

Department of Geological Sciences | P. David Polly 5

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

Department of Geological Sciences | P. David Polly 6

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

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