Abstract: This paper presents descriptions of Leptomitella spiralis sp. nov. from the early Cambrian Chengjiang biota, Yunnan
Province, China. The most typical character of L. spiralis sp. nov. is that the horizontal spicule bundles were spirally arranged around
the sponge body. Additionally, there are obvious distinctions in the external morphology and the types of spicules between L. spiralis sp.
nov. and other species within Leptomitella. New information obtained from L. spiralis sp. nov. increases the diversity of morphological
structure of Leptomitella, and also provides new data for exploring the early evolution and radiation of sponges in the Cambrian period.

Key words: Porifera, Leptomitella spiralis sp. nov., Chengjiang biota, Early Cambrian