On the genus Yangtzemerisma and related genera (Mollusca: Merismoconchia)

WA Museum Records and Supplements | Updated 8 years ago

ABSTRACT – Re-examination of the holotypes of the earliest Cambrian molluscs Yangtzemerisma rarum Yu, 1984 and Merismoconcha multisegmentata Yu, 1979, revealed some new structures such as soft-bodied organs and the number and position of the dorsoventral locomotive muscle scars. This new information is added to previous knowledge of the form of the shell, the elongate-ovate aperture, the growth lines and reticulate sculpture. Together indicate that the Merismoconchia differs from all other classes of the Phylum Mollusca, consistent with their status as an independent molluscan class.