Contents tagged with Mazon Creek
Created: 10/16/2013 Updated: 8/9/2016
How often do you think about the ground under your feet? About what it is composed of or how old the rocks are? Did you know that under your feet, there are not just rocks and soils, but fossils? Most of Illinois’ exposed rock layers, and the fossils found in them, were formed during the Carboniferous, approximately 355 to 290 million years ago. Check out the Paleontology Portal’s website about Illinois’ paleontology and geology, http://www.paleoportal.org/index.php?globalnav=time_space§ionnav=state&name=Illinois.
The Chicago Academy of Sciences and its Peggy Notebaert Nature Museum (CAS/PNNM) has over 22,000 fossils in its collection, most of which were collected from sites in the Midwest. To celebrate National Fossil Day, here are some specimens from CAS/PNNM’s paleontology collection.
Macroneuropteris macrophylla, a Neuropteris-like group seed fern from the Braidwood flora of the Mazon Creek area, IL. Carboniferous, Francis Creek Shale.
Spirorbis sp. (on Stigmaria sp.), worms on root structure, from the Essex fauna and flora of the Mazon Creek area, IL. Carboniferous, Francis Creek Shale.
Lobatopteris lamuriana, a true fern from the Braidwood flora of the Mazon Creek area, IL. Carboniferous, Francis Creek Shale.
Hystriciola delicatala, an annelid worm from the Essex fauna of the Mazon Creek area, IL. Carboniferous, Francis Creek Shale.
Annularia sp. specimens collected by Jonathan H. Britts from Henry County, MO.
Pecopteris vestita, a fern leaf collected by Jonathan H. Britts from Henry County, MO.
Pentremites obesus, a blastoid from Anna, IL. Mississippian, Chester Limestone.
Platystrophia acutilirata, brachiopods collected from Cincinnati, OH. Ordovician, Cincinnati Limestone.
Conularia crawfordsvillensis, (animal) collected from Crawfordsville, IN. Mississippian, Keokuk Group.
Phillipsia bufo, a trilobite collected from Crawfordsville, IN. Mississippian, Keokuk Group.
Stop in at the Nature Museum for a visit to see fossils up close. Here are a few of the fossils you can find on display:
Mammut giganteus, mastodon mandible and tooth from Macon County, IL
Receptaculites oweni, fossilized coral collected from Galena, IL
Tremanotus chicagoensis, gastropod (snail) specimen from Bridgeport, IL
Lepidodentron aculeatum, fossilized bark collected in Orange County, IN
Calymene niagarensis, trilobite specimens collected from section 6 of the drainage canal, Chicago, IL
Want to learn more about the fossils under your feet?
Gugilotta, Guy. “The World’s Largest Fossil Wilderness.” Smithsonian Magazine, July 2009. [Smithsonian.com, http://www.smithsonianmag.com/history-archaeology/Phenomena-Forest-Primeval.html]
“How Do We Know? – Fossils” webpage on MuseumLink Illinois site. Illinois State Museum, 2000. [http://www.museum.state.il.us/muslink/forest/htmls/how_foss.html] Information about how fossil pollen is used to study past environments.
Wittry, Jack. Mazon Creek Fossil Fauna. Illinois: ESCONI and Northeastern Illinois University, 2012. * Includes photographs of specimens from the CAS/PNNM collection!
Dawn RobertsView Comments
Created: 5/24/2013 Updated: 8/10/2016
Fossilization is a rare process. In fact, most of the plants, animals, and insects that existed on earth have not been retained in the fossil record because the conditions required must come together with such precision and timeliness that most just miss the boat. Occasionally, a fossil is produced – a leaf, a tooth, maybe a partial skeleton. From these, paleontologists try to piece together the earth’s history.
Most of the time, it is the hard parts of an animal that are fossilized because bone and teeth don’t succumb to the decay process as quickly as the soft parts of an animal, such as muscle tissue. Think about a banana left out on your kitchen counter too long – it will rot away, decomposed by bacteria. Every once in a while though, the conditions are just right to where the fossilization process includes those soft parts. This is rare, but can provide a more complete picture of an animal or an entire paleo-ecosystem. These are truly a remarkable resource, permitting us to look back in time.
Fossils from the Mazon Creek area in Illinois are associated with the Francis Creek Shale formation and date to approximately 307 million years ago, during the Pennsylvanian. This site is unique in that the fossil assemblage includes the preservation of soft tissue, even of animals such as worms and jellyfish! This paleontological site is called a “lagerstätten” or “mother lode” due to the diversity of the flora and fauna represented. Such sites are recognized worldwide as having importance for our national heritage and the process of understanding earth’s history.
Here are a few of the fossil specimens from the Mazon Creek area in the Academy’s museum collections:
Mazonomya mazonensis -- a clam
Euphoberia sp. -- a spiny millipede
Tullimonstrum gregarium - the "Tully Monster",
a carnivorous marine soft-bodied animal, and the Illinois state fossil
Lobatopteris sp. -- a fern
Annularia stellata -- a plant similar to a horsetail
Dawn RobertsView Comments