Fig.2. Distribution of graptolite or anoxitropic biofacies in the Early Paleozoic. Time intervals from Harland et al. (1982). Relative abundance of species level derived for
(1) agnostics: Whittington (1954);
(2) graptolites: Berry (this paper);
(3) styliolinids: Lutke (1979); and
(4) ammonoids: House (1985).
Representative figured organisms are not to scale. Drawings are modified from (a) agnostics: Moore (1959); (2) graptolites: Bulman (1970); (3) styliolinids: Lutke (1979); and (4) ammonoids: Moore (1957).