_(Mazon_Creek_Lagerst%C3%A4tte,_Middle_Pennsylvanian;_Mazon_Creek_area,_Illinois,_USA)_1.jpg)
This is a list of the biota of the Mazon Creek Fossil Beds, a Carboniferous lagerstätte located in Grundy County, Illinois. The site is famous for its exceptional preservation of soft bodied fossils inside of ironstone concretions, and was one of the first fossil sites discovered to preserve soft bodied fossils.
The Mazon Creek Fossil Beds are around 309-307 million years old, being approximately Moscovian in age. During the Carboniferous, this area was a lush, tropical delta system, about 10° north latitude of the equator. This ecosystem was formed by at least one river system that flowed in from the northeastern united states, and met the ocean to form an Estuarine environment. This large amount of habitat led to the creation of a very diverse ecosystem, which has been divided into two main sections, the marine Essex fauna, and the terrestrial/freshwater Braidwood fauna. Since the site's discovery in the early 20th century, more than 700 species of flora and fauna have been discovered, some of which have only been found at this site. Because of the diverse habitat types, many different groups, such as arthropods, mollusks, hemichordates, cnidarians, chondrichthyes, actinopterygii, and various other fish groups are represented. The flora is also diverse, with lycopsids, sphenopsids, pteridophyta, and pteridosperms being represented.[1][2][3][4]
Flora edit
Fauna edit
Chondrichthyes edit
A number of chondrichthyes (cartilaginous fish) are known from Mazon Creek, including a number of elasmobranchs and holocephalans.
| Chondrichthyes | ||||||
|---|---|---|---|---|---|---|
| Genus | Class | Higher taxon | Abundance | Notes | Images | |
| Bandringa | Chondrichthyes | Elasmobranchii
(placement uncertain) |
Various specimens | A bizarre elasmobranch that possessed a hyper-elongated upper jaw. Juvenile specimens are known from Mazon Creek, and adults are known from parts of Pennsylvania and Ohio, suggesting the area of Mazon Creek was a mating ground for these fish. | 
| |
| Dabasacanthus | Chondrichthyes | Elasmobranchii | A close relative of modern sharks, and a member of the Lonchidiidae family within the hybodontiformes order. | 
| ||
| Holmacanthus | Chondrichthyes | Elasmobranchii | Tiny hybodontiform. | |||
| Jimpohlia | Chondrichthyes | Holocephali | A bizarre, tadpole-like holocephalid fish that somewhat resembled the similar genus Delphyodontos. | 
| ||
| Polysentor | Chondrichthyes | Holocephali | A chimaera-like holocephalid fish, and is one of the various holocephalans known from Mazon Creek. | 
| ||
| Similhariotta | Chondrichthyes | Holocephali | A small sized chimaeriform fish that possessed an elongated upper jaw. | |||
References edit
- ^ Selden, Paul; Nudds, John (2012). "Mazon Creek". Evolution of Fossil Ecosystems (second ed.). Manson Publishing Ltd. pp. 94–96. ISBN 978-1-84076-623-3.
- ^ Schultze, H.-P.; Bardack, D. (1987). "Diversity and size changes in palaeonisciform fishes (Actinopterygii, Pisces) from the Pennsylvanian Mazon Creek fauna, Illinois, U.S.A.". Journal of Vertebrate Paleontology. 7 (1): 1–23. doi:10.1080/02724634.1987.10011635.
- ^ Joanne Klussendorf (March 30, 1995), National Historic Landmark Nomination: Mazon Creek Fossil Beds (pdf), National Park Service. Accompanying photos, from 1912 and 1991. (497 KB)
- ^ Nitecki, Matthew H.; Schram, Frederick R. (1976). "Etacystis communis, a Fossil of Uncertain Affinities from the Mazon Creek Fauna (Pennsylvanian of Illinois)". Journal of Paleontology. 50 (6): 1157–1161. JSTOR 1303556.