Fossils of the Burgess Shale

Vauxia: This bush-like, branching sponge of the Phylum Porifera, is composed of a tough spongin-like framework. This tough framework explains why this is the most common of the Burgess sponges. (Nudds and Selden, 2008).


Thaumaptilon: Of the Phylum Cnidaria, Thaumaptilon is a survivor of the Precambrian Ediacara fauna. It has a broad central axis with up to forty branches, each housing hundreds of individual star-like polyps. (Nudds and Selden, 2008).



Ottoia: Ottoia is the most abundant of the mud-dwelling worms, especially in the higher beds of the Burgess Shale. Of the Phylum Priapulida, they had a bulbous anterior proboscis surrounded by vicious hooks and spines. At the end of the proboscis is a mouth with sharp teeth with they often used to devour other specimens of Ottoia, as these animals were cannibals. (Nudds and Selden, 2008).



Hallucigenia: This species, of the Phylum Onychophora, is the most celebrated Burgess animal. This animal was named because it has a “dream-like” quality that seems unlike any other known animal. However, this was partly because it had been reconstructed upside down, standing on rigid spines and waving its tentacles in the water. Once additional specimens suggested reversing this interpretation, it was realized that this genus was a marine velvet worm, having actually crawled on its fleshy limbs and using its spines for protection as it scavenged for decaying food. (Nudds and Selden, 2008).



Marella: Of the Phylum Arthropoda, this small, feathery arthropod is often known as the “lace-crab”. It is the most common of the Burgess animals, with over 15000 specimens discovered, and as of yet is known from no other Cambrian deposit. Marella had 20 body segments each bearing a pair of identical legs, suggesting that this was a primitive arthropod, and could be ancestral to the three major groups of aquatic arthropods: crustaceans, trilobites, and chelicerates. (Nudds and Selden, 2008).



Sanctacaris: Sanctacaris represents the earliest known example of a chelicerate, the group containing spiders and scorpions. The large head shield protected six head appendages, five of which were spiny claws to assist in capturing prey. This gave this member of the Phylum Arthropoda the nickname “Santa Claws”. (Nudds and Selden, 2008).



Anomalocaris: Of the Phylum Lobopodia, the monster predator of the Burgess Shale does not resemble any known animal, and has long been considered an example of a short-lived experimental arthropod-like phylum. More complete specimens reveal this to be the largest known of the Burgess animals, reaching lengths of up to one meter. (Nudds and Selden, 2008).



Opabinia: This strange animal had five eyes on the top of its head and a long, flexible proboscis which terminated in a number of spines, apparently a grasping organ. Each of the body segments possesses lateral lobes with gills and a strange tail was formed by three posterior flaps. Some authorities now believe that it may be related to Anomalocaris and that both may be arthropods. (Nudds and Selden, 2008).



Wiwaxia: Of the Phylum Mollusca, this strange mud-crawling animal was protected from predators by its dorsal surface being covered by a coat of scale-like sclerites and a double row of pointed spines. The ventral surface was a soft foot similar to that of a slug or snail. The true affinities of Wixwaxia remain in doubt, although it is almost certainly related to the halkieriids. (Nudds and Selden, 2008).



Pikaia: This inconspicuous but vital element of the Burgess fauna is of the Phylum Chordata. Pikaia possed a stiff rod that runs along its dorsal margin. This sugests that it is a primitive Chordate, the phylum to which humans and all verbatrates belong, and shows that our ancestors were recognizably present during the Cambrian Explosion. (Nudds and Selden, 2008).



Nudds and Seldon. (2008). Fossil Ecosystems of North America: A Guide to the Sites and their Extraordinary Biotas. Chicago, The University of Chicago Press.

Vauxia photo from

Thaumaptilon photo from

Ottoia photo from

Marella photo from

Hallucgenia photo from

Sanctacaris photo from /

Anomalocaris photo from

Opabinia photo from

Wiwaxia photo from

Pikaia photo from

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