A Walking with Monsters - Life Before Dinosaurs PDVD 008
an extinct genus of anomalocarids, which are thought to be related to arthropods. 



Anatomy Edit

The first fossils of Anomalocaris were found in the Ogygopsis Shale by Joseph Frederick Whiteaves. Charles Doolittle Walcott found even more in the Burgess Shale. The mouth, feeding appendages, and tails were found, and once were thought to be 3 separate creatures, but this was later proven wrong in a 1985 Journal Article, by Harry B. Whittington, and Derek Briggs. Anomalocaris is thought to be a carnivore, and that it swam through the water by moving the lobes on the sides of its body. Its large head had (most likely) compound eyes, and a disk-like mouth. The mouth was made up of 32 overlapping plates, 4 large, and 28 small, that looked like a pineapple ring with the center replaced by a series of serrated prongs. The mouth could constrict to crush prey, but never completely close, and the tooth-like prongs continued down the walls of the gullet. Two large "arms" (up to seven inches in length when extended) with barb-like spikes were positioned in front of the mouth, and were probably used these to grab prey and bring it to its mouth. The tail was large and fan-shaped, and along with undulations of the lobes, was probably used to propel the creature through Cambrian waters. Stacked lamella of what were probably gills attached to the top of each of a total of eleven lobes. For the time in which it lived, Anomalocaris was a truly gigantic creature, reaching lengths of up to one meter.

Discovery Edit

Anomalocaris has been misidentified several times, in part due to its makeup of a mixture of mineralized and unmineralized body parts; the mouth and feeding appendage was considerably harder and more easily fossilized than the delicate body. Its name originates from a description of a detached 'arm', described by Joseph Frederick Whiteaves in 1892 as a separate crustacean-like creature due to its resemblance to the tail of a lobster or shrimp. The first fossilized mouth was discovered by Charles Doolittle Walcott, who mistook it for a jellyfish and placed the genus Peytoia. Walcott also discovered a second feeding appendage but failed to realize the similarities to Whiteaves discovery and instead identified it as feeding appendage or tail of the extinct Sidneyia. The body was discovered separately and classified as a sponge in the genus Laggania; the mouth was found with the body, but was interpreted by its discoverer Simon Conway Morris as an unrelated Peytoia that had through happenstance settled and been preserved with Laggania. Later, while clearing what he thought was an unrelated specimen, Harry B. Whittington removed a layer of covering stone to discovered the unequivocally connected arm of thought to be a shrimp tail and mouth thought to be a jellyfish. Whittington linked the two species, but it took several more years for researchers to realize that the continuously juxtaposed Peytoia, Laggania and feeding appendage actually represented a single, enormous creature. According to International Commission on Zoological Nomenclature rules, the oldest name takes priority, which in this case would be Anomalocaris. The name Laggania was later used for another genus of anomalocarid. "Peytoia" has been modified into Parapeytoia, a genus of Chinese anomalocarid. Anomalocaris is placed in the extinct family Anomalocaridae, and is now considered to be related to modern arthropods. Stephen Jay Gould cites Anomalocaris as one of the fossilized extinct species he believed to be evidence of a much more diverse set phyla that existed in the Cambrian era (discussed in his book Wonderful Life), a conclusion disputed by other paleontologists. 


Anomalocaris in Popular Culture Edit

The Pokemon Anorith and Armaldo are based off Anomalocaris.

Many Anomalocaris were featured in the BBC Documentary Walking with Monsters, and one was attacked by a school of Haikouichthys.