New tubicolous problematic fossil with some 'lophophorate' affinities from the Early Cambrian Chengjiang biota in south China

摘要

A new tubicolous problematic fossil Cambrocornulitus rarus n. gen. n. sp. (Cornulitida?) from the Early Cambrian Chengjiang biota with well-preserved soft body tissues is described. This tubicolous fossil probably had a biomineralized shell, and shares some affinities with cornulitids and lophophorates. C. rarus has a straight to curved, conical tube with external transversal rings (ridges), longitudinal ribs (striae) and possibly microlamellar wall structure. The preserved soft body of C. rarus exhibits several important morphological characteristics, such as a possible lophophore and nephridial ridges. The new genus had a somewhat similar mode of life to the gregarious type of cornulitids. Some of the studied tubes of C. rarus show malformed development.