Anomalocaris

Anomalocaris ("unlike other shrimp", or "abnormal shrimp") is an extinct genus of radiodont, an order of early-diverging stem-group arthropods. It is best known from the type species A. canadensis, found in the Stephen Formation (particularly the Burgess Shale) of British Columbia, Canada. The species A. daleyae is known from the somewhat older Emu Bay Shale of Australia. Other remains are known from China and the United States. Originally, several fossilized parts discovered separately (the mouth, frontal appendages and trunk) were thought to be three separate creatures, a misapprehension corrected by Harry B. Whittington and Derek Briggs in a 1985 journal article. Like other radiodonts, Anomalocaris had swimming flaps running along its body, large compound eyes, and a single pair of segmented, "frontal appendages", which in Anomalocaris were used to grasp prey. Measuring up to long excluding frontal appendages and tail fan, A. canadensis is one of the largest animals of the Cambrian, and thought to be one of the earliest examples of an apex predator, though others have been found in older Cambrian lagerstätten deposits. From the start, Anomalocaris fossil was misidentified, followed by a series of misidentifications and taxonomic revisions. As Stephen Jay Gould, who popularised the Cambrian explosion in his 1989 book Wonderful Life, appropriately described:[The story of Anomalocaris is] a tale of humor, error, struggle, frustration, and more error, culminating in an extraordinary resolution that brought together bits and pieces of three "phyla" in a singe reconstructed creature, the largest and fiercest of Cambrian organisms.Anomalocaris fossils were first collected in 1886 by Richard G. McConnell of the Geological Survey of Canada (GSC). Having been informed of rich fossils at the Stephen Formation in British Columbia, McConnell climbed Mount Stephen on 13 September 1886. He found abundant trilobites, along with two unknown specimens.