|Period||Middle Cambrian 507-505 Million Years Ago (Wheeler - Burgess Shale)|
In 1938 they founded a fosill of a Selkirkia.Fieldia, Selkirkia, Louisella, Ancalagon, Scolecofurca, and Lecythioscopa, the organism was originally classified into a clade termed the archaeopriapulida, a stem group to the Priapulids proper. However, the morphological similarity of these organisms to their modern cousins is remarkable, especially for the Burgess Shale, and their similarity to the modern genus Maccabeus suggests that they are in the Seticoronaria stem group, and thus are true crown-group priapulids. A phylogenetic analysis does not provide a great deal of resolution to the relationships between these basal worms.
PaleobiologyOttoia was an 8 cm predatory worm that lived most of its life in burrows. Like most worms, it was round and lengthy, with no backbone. It also lived in small U-shaped burrows that it had dug in the sea floor, which it would also use as ambush hiding places. It lived in the Mid Cambrian, about 520 million years ago, and lived alongside invertebrates like Anomalocaris and Hallucigenia. One feature that seperated it from most worms is that it was a highly-active ambush predator towards snail-like mollusks. It had a round mouth piece towards its head that had 40 to 50 spikes on it, possibly for grasping onto struggling prey. The posterior end of Ottoia also had small hooks, which likely acted as anchors to hold itself in the ground. Fossil evidence also suggests that when needed, Ottoia was cannibalistic, and would kill and eat its own. They eat Waptias, Trilobites and Aysheaia. They maybe eat Fieldia (Because Fieldia was a small Priapulid worm of the Cambrian). They can get eaten by Anomalocaris, Peytoia and Hurdia.
In Popular Culture
An Ottoia was eating a mollusc (In the picture in the Infobox) and got eaten by a Hurdia in the Website The Burgess Shale on Virtual Sea Odyssey on the Predators or Early Life Predators.
It was a major inspiration for the giant priapulid flesh eating monsters in the 2005 Peter Jackson remake of King Kong (the ones living at the bottom of the cess pit)