The Yunnanozooan is a suspected chordate or hemichordate from the Lower Cambrian beds of Xiangchiang[?], Yunnan province, China.
It is similar to the form Haikouella which is almost certainly
a vertebrate. There are anatomical differences from
Haikouella including a smaller stomach, and much larger (1mm)
pharyngeal teeth. Yunannozoon is not known for sure to possess
many features like heart, gills, etc. that are known from well
preserved specimens of Haikouella. Yunnanozoon
somewhat resembles the Middle Cambrian Pikaia[?] from British
Columbia's Burgess shale. 13 pairs of symmetrically arranged gonads
are identified as are possible gill slits.. However, some authors think
that Yunnanozoon is closely related to the chordate
Haikouella and that Yunnanozoon is probably a
chordate rather than a hemichordate.
There is one species Yunnanozoon lividum (Chen et al., 1995).
External link