bottom and dorsal views
General abundance:
Common
Viewer Comments:
The A. varica appears to
have some serpulid worm tube
attached to them. The A. concentrica appears to be free
of commensals. It might be an interesting study to see
if one is wormy and the other worm free---that may
have as much meaning as morphologic features.
Dr. Roger Pabian
Reference:
Desmoinesian Brachiopoda and Mollusca
from Southwest Missouri
by: Richard D. Hoare
Page 246-247, figure 6
Pennsylvanian
Fossils of Missouri