Mollisonia
- North America
- China
Molli Sonia is an extinct genus of uncertain position within the arthropods ( Arthropoda ).
Features
Representatives of the genus Molli Sonia were oblong, almost rectangular in dorsal and almost triangular in transverse view. The dorsal exoskeleton consisting of a head shield, seven thoracic segments ( tergites ) and a tail plate, had an axial ridge. The thoracic segments were arranged in length and width about equal to all. The tail plate had on the surface two or three pairs of transverse extensions.
Extremities have not been preserved.
Locations
Species of the genus were in the Burgess Shale in Canada, United States, found in the Kaili Formation in China and in the Wheeler Formation in Utah.
System
Molli Sonia shows some similarities with Corcorania Jell, 1980, Kuamaia Hou, 1987 and Sinoburius Hou, Ramsköld & Bergström, 1991, but not, however einordneten with Xandarella Hou et al., 1991, which latter two Hou and Bergström in the same subclass Petalopleura. However, as with all finds the extremities missing, Molli Sonia could not be properly classified. Simonetta and Delle Cave they put 1975 in the monotypic order Mollisoniida with the family Mollisoniidae.
A distinction is currently 3 types:
- Molli Sonia gracilis Walcott, 1912
- Molli Sonia sinica Zhang et. al, 2002
- Molli Sonia symmetrica Walcott, 1912 (type ) ( = Molli Sonia rara Walcott, 1912)