CNIDARIAN FOSSIL RECORD

Cnidaria: Fossil Record

Many of the very best cnidarian fossils date back to the time when animals first appear in the fossil record, the Vendian. Since then, the fossil record of cnidarians without mineralized skeletons is quite sparse, and restricted to unusual sites with excellent fossil preservation.

On the other hand, cnidarians which possessed hard skeletons, in particular the corals, have left a significant legacy of their existence. While a few mineralized coral-like fossils have turned up in the Cambrian Period, identifiable corals began an evolutionary radiation in the Early Ordovician. These Paleozoic corals included taxa known as tabulate corals, rugose corals, and heliolitid corals. All these forms were wiped out at the end of the Permian Period, in a mass extinction event that claimed something like 95% of all marine invertebrate species.

Scleractinian corals first appear in the Middle Triassic, about 15 milion years after the Permian extinction. They rapidly expanded into ecological niches once dominated by tabulate and rugose corals, and became the dominant hermatypic (reef-building) organisms in shallow tropical marine habitats. Because corals are sensitive to changes in light, temperature, water quality, and salinity, their fossils provide information that can be used to interpret climate and geography of past environments.

Nemaia simplexClass Scyphozoa (?)Precambrian, VendianWhite Sea Region, Russia http://www.fossilmuseum.net/fossils/Cnidaria/Nemaia-simplex/Nemaia.htm

(1 ) Mawsonites spriggi -fossil cast late-neoproterozoic South-Australia---display-at-smithsonian-museum-of-natural-history-august-2010

http://en.wikipedia.org/wiki/Mawsonites

http://geoinfo.amu.edu.pl/wngig/ig/UAM_Ing/VanLoon/2008_GondwanaRes%2014_175_182.pdf

(47) Mawsonites spriggi / Fossil Jelly fish

Utah fossil –jellyfishes http://news.nationalgeographic.com/news/2007/10/071031-jellyfish.html

Astropolithon These "jellyfish" in Cambrian rocks in Saint John, New Brunswick, are now interpreted as gas

escape structures.

http://jsedres.geoscienceworld.org/content/49/3/1029.abstract

http://journals.hil.unb.ca/index.php/ag/article/view/1578

laotira_Laotira is a "classic" medusoid that is now considered to represent a "non-jellyfish." It was described by Walcott from the Cambrian of Alabama, but has since been re-interpreted as a burrow structure. (Field Museum of Natural History specimens)

fossil jellyfish.

jellyfish_fossils cambrianFossil jellyfish from the Cambrian Mt. Simon Sandstone in mid-Wisconsin. These are imprints, up to a meter across, of the bell and its anatomy preserved as the jellyfish were stranded on a shallow tidal sand flat some 525 million years ago. These and other soft-bodied fossils are being studied in Jere Lipps's lab in the Department of Integrative Biology. This work on fossils is combined with molecular sequencing of basal invertebrates to get a clearer understanding of the early evolution of animals.

Photo by Lisa-ann Gershwin and submitted by Jere Lipps.Posted April 12th, 2007 by monica Thumbnail 

Jellyfish.Wisconsin -500MYAhttp://www.anomalies-unlimited.com/Science/FossilJelly.html

Xianguangia sinicaPrimitive Sea AnemoneEarly CambrianChengjiang Biota, Chinahttp://www.fossilmuseum.net/Fossil_Sites/Chengjiang/Xianguangia-sinica/Xianguangia.htm

http://www.fossilmuseum.net/Fossil_Sites/Chengjiang/Xianguangia-sinica/Xianguangia.htm

Ordovician Cnidarian FossilsThe Cnidarian phylum is found exclusively in aquatic environments. It includes corals, jellyfish, anemones, and medusae. The phylum's name is derived from the Greek word "cnidos" which means stinging nettle and is appropriately named due to the nematocysts that eject barbed threads with poison. Members of this group are either radially or biradially symmetric. Members typically fall into two groups, medusae such as jellyfish, and polyps, such as corals.

CORALS

Class:AnthozoaSubclass:ZoanthariaOrder:Rugosa

Grewingkia canadensis

First two specimens are a solitary rugose coral specimen about 7.5 cm in length. Internal structure not visible since it is encased in matrix. Small amounts of matrix still remain on exterior.Third specimen is a horn coral 4.34 cm in length.Fourth specimen is 6.06 cm in length.Fifth specimen is 5.96 cm in length and has been broken to reveal some of the internal structure

Class:AnthozoaSubclass:RugosaOrder:Stauriida

Favistina stellata

Nearly spherical coral about 3.25 cm in diameter.

 

godzillus.

Paraconularia-derwentensis-L.jpg

Paraconularia derwentensisClass StaurozoaPermianTasmania, Australiahttp://www.fossilmuseum.net/fossils/Cnidaria/Paraconularia/paraconularia.htm

Eldonia Berberi: Devonian: Alnif,Morocco

Eldonia is a great example of a problematic fossil organism. Specimens are preserved as a nearly flat impression. Distinct strands radiating from the center are interpreted as radial canals on both the ventral and dorsal surface. There is still considerable debate among paleontologist as to whether they are jellyfish or some other soft-bodied animal.

eldonia berberi .jpgMorocco Jellyfish

1385 Essexella asheraeMazon Creek Jellyfish Replica 

Jellyfish are extremely rare in the fossil record. This is hardly surprising, considering they completely lack hard parts, and the tissues they do possess are gelatinous.

One of the most famous deposits containing fossil jellyfish is the Pennsylvanian-aged Mazon Creek Lagerstätte near Chicago, Illinois. In the Mazon Creek area, the Francis Creek Shale consists of concretionary gray shales. The Francis Creek concretions are sideritic, and can be fossiliferous or unfossiliferous. The fossiliferous

concretions contain land plants and terrestrial & marine animals, including nonmineralizing organisms.

The most abundant marine organisms in the Mazon Creek biota are jellyfish. Many Mazon Creek jellyfish specimens do not have many diagnostic features, and are affectionately referred to as "blobs" by local fossil collectors ("blob A", "blob B", "blob with character", etc.).

Stratigraphy: Francis Creek Shale Member, Carbondale Formation, Desmoinesian Stage (= Westphalian D), upper Middle Pennsylvanian

octomedusa.http://ancientshore.com/2010/12/05/recognizing-fossil-jellyfish/

Octomedusa pieckorum is a “classic” fossil jellyfish from the Upper Carboniferous Mazon Creek (Carbondale Formation) of Illinois. (Royal Ontario Museum, ROM 47540; scale on right is in centimetres)

Rhizostomites admirandus Cast  Jurassic.: Solnhofen Formation Germany The original fossil is housed at a museum in California.