Spartobranchus

Spartobranchus is an extinct genus of acorn worm from the Cambrian Burgess Shale. It contains the species Spartobranchus tenuis. It is similar to the modern representatives of the family Harrimaniidae, although distinguished by living in branching fibrous tubes.^[1] It is a likely stem-member of the acorn worms, although it is somewhat intermediate between them and pterobranchs. Studies show that the ability to create tubes were lost in the line leading to modern acorn worm, but remained in the pterobranchs. However recently Antarctic torquatorids have been found that also make tubes.^[2]

Spartobranchus Temporal range: Upper Cambrian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Hemichordata
Genus:	†Spartobranchus Caron et al, 2013
Species:	†S. tenuis
Binomial name
†Spartobranchus tenuis Caron et al, 2013

Description

Detailed analysis shows that Spartobranchus tenuis had a flexible body consisting of a short proboscis, a collar and a narrow elongated body that ended in a bulbous structure that may have served as an anchor. The most complete specimens reached 10 cm (3.9 in) long, with a proboscis roughly half a centimeter in length.^[1]