Megacheira is an extinct class of predatory euarthropod

Arthropod

An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...

s that possessed a pair of short enlarged appendage

Great appendage

Great appendages are large claw-like appendages which attach to the heads of the "great appendage arthropods", a group whose monophyly is debated, but which includes the anomalocaridids...

s (the source of the class' name). They were found in marine environments throughout the world from the lower to middle Cambrian

Cambrian

The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...

, and were important components of several faunas, including the Burgess

Burgess Shale

The Burgess Shale Formation, located in the Canadian Rockies of British Columbia, is one of the world's most celebrated fossil fields, and the best of its kind. It is famous for the exceptional preservation of the soft parts of its fossils...

 and Maotianshan Shales

Maotianshan shales

The Maotianshan Shales are a series of lower Cambrian deposits in the Chiungchussu formation, famous for their Konservat Lagerstätten, or high number of fossils preserved in place...

 lagerstattens. Genera referred to the class include Leanchoilia

Leanchoilia

Leanchoilia is a four-eyed arachnomorph arthropod known from the Cambrian Burgess shale. It was about 5cm long and had long, whip-like feelers mounted on frontal arm-like appendages. Its guts are sometimes preserved in three dimensions....

, Alalcomenaeus

Alalcomenaeus

Alalcomenaeus is one of the most widespread and longest surviving arthropod genera of the Early and Middle Cambrian. Known from over 300 specimens in the Burgess shale, and the Chengjiang, it bears great similarity to the opabiniids.-Morphology:...

and Yohoia

Yohoia

Yohoia is a tiny, extinct animal from the Cambrian period that has been found as fossils in the Burgess Shale formation of British Columbia, Canada. It has been placed among the arachnomorphs, a group of arthropods that includes the chelicerates and trilobites. Their sizes range from 7 to 23 mm...

, Fortiforceps and Jianfengia.

External links

• http://findarticles.com/p/articles/mi_qa3790/is_199901/ai_n8827810/pg_3