Mazon Creek Animals

Family Tree of Mazon Creek Animals

The Mazon Creek fauna is extremely diverse. According to Nitecki (1979) more than 320 species of animal have been identified (or originally described) from the deposit.

Scientists studying the fauna have divided it into two components. These are the Essex and Braidwood faunas. The Essex fauna contains the marine organisms that would have lived in the shallow bays. The Essex fauna includes such animals as jellyfish, worms, snails, clams, shrimp, and fish.

The Braidwood fauna consists of land and freshwater-dwelling organisms that washed into the bays. The Braidwood fauna includes insects, millipedes, centipedes, scorpions, spiders, spider relatives, amphibians, freshwater fish, shrimps, freshwater horseshoe crabs, and ostracodes.

The following Web pages discuss the fossil animals in the following categories with fossil examples:

Cnidarians - jellyfishes, corals, sea anemones, and hydroids
Annelids - worms
Arthropods -
crustaceans (shrimp, crayfish, lobsters, crabs, barnacles, and sowbugs),
chelicerates (horseshoe crabs, sea scorpions, scorpions, spiders, and mites),
myriapods (centipedes and millipedes),
insects (dragonflies)

Molluscs - snails, clams, squid, and chitons
Chordates - fish
Tullimonstrum gregarium - this soft-bodied animal has not been classified and is unique to the Mazon Creek localities.