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Home | Exhibits | Life Through Time Exhibit | Mississippian |
| Devonian |
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During the Mississippian* sea lilies dominated the seas and reptiles began to appear on land, along with ferns. Crinoids and their relatives, blastoids, were so widespread in North America that the Mississippian is known as the Age of Crinoids. We thus infer a time of warm, clear seas since Because crinoids are filter feeders the seas must have been relatively clear, while their need for high calcium carbonate (CaCO3) concentrations to build their skeletons points to a warm water environment. The generally open communications between the continental shelves of this Period resulted in a marine fauna which was generally distributed Worldwide.
Although the Devonian ended with a series of glaciations and extinction events, the Mississippian began glaciation free. This is the last Period to see limestone (the major Mississippian rock type) deposited by widespread seas on the North American continent.*The Mississippian was bamed for rocks in the upper Mississippi Valley by Winchell in 1870.
Mississippian Animal (Metazoan) Fossils |
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Trilobites (ToL: Trilobites<Arthropoda<Ecdysozoa<Bilateria<Metazoa<Eukaryota) |
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Trilobites had suffered significant extinctions at the end of the Devonian, suffering over a 50% loss of families. There is a single Mississippian trilobite, Griffithides bufo, displayed. |
Echinoderms (ToL: Echinodermata<Deuterostomia<Bilateria<Metazoa<Eukaryota) |
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Crinoids (Crinoidea). As befits the Age of Crinoids (Crinoidea). a wide range of fossil crinoids (particularly the stemmed forms, or sea lilies) are displayed: Abatocrinus sp., Dichocrinus striatus and Cryptoblastus melo, Aorocrinus immaturus and Platycrinites symmetricus, Taxocrinus colletti, Barycrinus princeps, Barycrinus asteriscus, Sea Lily, Sea Lily. A more common fossil than the body of the sea lilies are pieces of their stems. Here we see a collection of crinoid stems, an assemblage of crinoid stems, and a slab with crinoid stems. |
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Blastoids (Blastoidea). The related blastoids, common during this Period, are also well represented: Globoblastus norwoodi, Pentremites godoni major, and Pentremites pyriformis. |
Mollusks (ToL: Mollusca<Lophotrochozoa<Bilateria<Metazoa<Eukaryota) |
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Gastropods (Gastropoda) are represented by a single snail, Anematina proutana. |
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Cephalopods (Cephalopoda): Ammonoids lost almost all of their families in the Devonian extinction. Muensteroceras parallelum represents the survivors in this display. |
Brachiopods (ToL: Brachiopoda<Lophotrochozoa<Bilateria<Metazoa<Eukaryota) |
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Brachiopods suffered important losses in the Devonian extinction, but many families survived into the Mississippian. A single species is represented by a pair of small specimens in this case. |
Corals (ToL: Cnidera<Metazoa<Eukaryota) |
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Cnidarians (corals): Less than half of the coral families survived into the Mississippian. Specimens of both a solitary horn coral and Lithostrotion proliferum, a colonial form are shown. |
The engravings are from Dana, James D. (1870) Manual of Geology and Le Conte, Joseph (1898) A Compend of Geology.
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Last modified 29 January 2007 | ©1998, HSU NHM
