门: 鳃曳动物门
纲: 未定
目：未定
科: 未定
属：奥托属
种: 奥托虫
描述:
奥托虫的咽部可以收缩回躯干中，尾部的凸出的光滑部分也可以收缩。奥托虫个体最大可达15cm，最小的个体只有1cm。吻部分为排列着28列钩状刺的翻吻，光滑的领和分布着咽齿的咽部。躯干是环状的，尾部有八个粗壮的尾刺。奥托虫经常被发现呈U形埋藏，并且在身体中央可以看到明显的消化道。
Phylum: Priapulida
Class: uncertain
Order: uncertain
Family: uncertain
Genus: Ottoia
Specie: Ottoia prolifica
Description:
Ottoia is a priapulid worm with a proboscis that could be inverted into the trunk; a short posterior tail extension could also be inverted. Ottoia reaches 15 cm in length; the smallest specimens are just 1 cm long. The proboscis can be divided into an introvert adorned with 28 rows of spines, a smooth collar and a pharynx with pharyngeal teeth. The trunk is annulated, and bore two sets of four hooks arranged in a ring towards the rear end. The worms are usually found curved into a U-shape, with their sediment-filled guts often visible running down the centre of the organism.
时代：中寒武世，Bathyuriscus-Elrathina带到 Ptychagnostus punctuosus带，约5.05亿年前
主要产地: 加拿大布尔吉斯生物群
Age: Middle Cambrian, Bathyuriscus-Elrathina Zone to Ptychagnostus punctuosus Zone (approximately 505 million years ago).
Principal localities: Burgess Shale, British Columbia, Canada
BANTA, W. C. AND M. E. RICE. 1970. A restudy of the Middle Cambrian Burgess Shale fossil worm, Ottoia prolifica. International Symposium on the Biology of the Sipuncula and Echiura 2, Kotor: 79-90.
CARON, J.-B. AND D. A. JACKSON. 2008. Paleoecology of the Greater Phyllopod Bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology, 258: 222-256.
CONWAY MORRIS, S. AND J. S. PEEL. 2009. New Palaeoscolecidan Worms from the Lower Cambrian: Sirius Passet, Latham Shale and Kinzers Shale. Acta Palaeontologica Polonica, 55(1): 141-156.
HARVEY, T. H. P., X. DONG AND P. C. J. DONOGHUE. 2010. Are palaeoscolecids ancestral ecdysozoans? Evolution & Development, 12(2): 177-200.