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Fossil Gallery - Crinoids, Blastoids, Cystoids
Echinodermata
(Phylum)
Red text = needs information
Fossil identification by Jo Cox unless otherwise noted
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Crinoids, Blastoids, and Cystoids are animals even though they resemble plants and have been called sea-lilies and feather stars. 12.0pt;color:black"> They have five-part symmetry and are kin to urchins and starfish. Crinoids plates are the most common Pennsylvanian fossils. These soft bodied animals had a skeleton structure of plates and spines covered with a leathery skin. The main body is made up of a flat cup, a ring of flexible arms, and a mushroom-shaped tube (tegmen). The top of the tegmen is often ringed with spines that may have held an umbrella membrane. Some species cups are ringed in triangular spines, while others are rather long. The arms often divide, sometimes several times. The surfaces of the tegmen and inner arms grew celia (hairs) that directed water currents toward the animal's mouth. The bottom of the cup attaches to a long stem. The stem was made up of discs that can be round, oval, spiraled, or stars, they often have a hole in the center. Stem segments are sometimes called “pop rocks” because they explode in a fire, like popcorn. A root-like structure anchored the animal to the sea floor but did not absorb nutrients like a plant's root. Blastoids resemble crinoids, but their body was more compact and topped by a brush-like strainer instead of arms. Cystoids, also called sea-lilies, have a ball-shaped body (calyx) that is made of plates. This animal would have attached itself to the ocean floor by a segmented stem and root-like anchor. |
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Crinoidea
(Class)
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Crawford villensis Period: Mississippian, Edwardsville Formation Location: Montgomery Co., Indiana (purchased) Collection: Judie Ostlien Size: 162 mm tall block |
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? (like Hydreimocunus sp.) Period: Pennsylvanian Location: north of Cisco, Texas Collection: Jo Cox Size: ? mm (left), ? mm (center), 14 mm wide (right) |
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Description: assorted crinoid plates |
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? (like Hydreimocunus sp. and Plaxocrinus macrospiniferus) Period: Pennsylvanian Location: north of Cisco, Texas Collection: Jo Cox Size: ? mm long (left and longest in 2nd photo) |
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Description: crinoid tegmen spines |
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? Period: Pennsylvanian Location: north of Cisco, Texas Collection: Jo Cox Size: 28 mm long |
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Description: crinoid anal or brachial spine. The base (large end) is broken off. The point end broke while the animal still lived and started regenerating. |
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Erisocrinus elevatus Period: Pennsylvanian Location: near Brownwood, Texas Collection: Hardin-Simmons University Size: 28 mm wide |
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Description: Crinoid dorsal cup (base of head) |
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? Period: Pennsylvanian Location: near Brownwood, Texas Collection: Hardin-Simmons University Size: 16 mm wide |
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Description: Crinoid dorsal cup (base of head) |
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Delocrinus sp. Period: Pennsylvanian Location: near Brownwood, Texas Collection: Hardin-Simmons University Size: 16 mm wide |
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Description: Crinoid dorsal cup (base of head) |
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? Period: Pennsylvanian Location: north of Cisco, Texas Collection: Jo Cox Size: 12 mm Dia (right segment), 16 mm long stem, 55 mm long stem (longest) |
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Description: assorted crinoid stems |
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? Period: Pennsylvanian Location: near Brownwood, Texas Collection: Hardin-Simmons University Size: 16 mm Dia., 16 mm Dia., 14 mm Dia. |
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Description: Crinoid stem segments |
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? Period: Pennsylvanian Location: ? Collection: Hardin-Simmons University Size: 54 mm tall |
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Description: Crinoid stem |
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? Period: ? Location: Taylor Co., Texas Collection: Judie Ostlien Size: 5 mm Dia. |
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Description: Impression of a crinoid stem segment in chert |
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Blastoidea
(Class)
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? Period: Pennsylvanian Location: ? (purchased) Collection: Jo Cox Size: ? mm tall> |
X |
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Description: the body (theca) |
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? (like Troosticrinus sp.) Period: ? Location: ? Collection: Hardin-Simmons University Size: 22 mm tall x 22 mm wide |
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Description: the body (theca) |
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Cystoidea
(Class)
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? Period: ? Location: ? Collection: Judie Ostlien Size: ? mm Dia. |
X |
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