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 simplex
Class Scyphozoa (?)
Precambrian, Vendian
White 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 cambrian
Fossil 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 -500MYA
http://www.anomalies-unlimited.com/Science/FossilJelly.html
Xianguangia sinica
Primitive Sea Anemone
Early Cambrian
Chengjiang Biota, China
http://www.fossilmuseum.net/Fossil_Sites/Chengjiang/Xianguangia-sinica/Xianguangia.htm
http://www.fossilmuseum.net/Fossil_Sites/Chengjiang/Xianguangia-sinica/Xianguangia.htm
Ordovician Cnidarian Fossils
The 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:Anthozoa
Subclass:Zoantharia
Order: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:Anthozoa
Subclass:Rugosa
Order:Stauriida
Favistina stellata
Nearly spherical coral about 3.25 cm in diameter.
godzillus.
Paraconularia-derwentensis-L.jpg
Paraconularia derwentensis
Class Staurozoa
Permian
Tasmania, Australia
http://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 .jpg
Morocco Jellyfish
1385 Essexella asherae
Mazon 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.