It appears that the rigid, en echelon shields formed by jointed arm branches are an adaptation to strengthening the crown and gathering food in highly variable, strong currents in a shallow reef or bioherm
This microfacies is interpreted to be formed by in-situ organisms as an organic reef (Bioherm
) in margin of platform and was located above the fair-weather wave base (FWWB).
Wilson  describes the reef platform as, "a bioherm
We prefer to use the term bioherm
to describe these features as they are considered to be composed of trapped sediments and both living and dead bivalves, while others (Paull et al.
schmitti was collected from a wide sabellarian bioherm
in Burrows Channel, Fidalgo Island (northern Puget Sound, Washington).
The lithological change from oolitic grain banks during Cambrian Series 3 to bioherm
bearing massive micrites and calcareous mudstone with lenses of edgewise conglomerates in Changshan and Fengshan formations represents the depositional pattern of the skeleton-poor stormy sea during the Furongian marked by an increase in microbial carbonate buildups.
The best exposed bioherm
is a biodetrital mound located in a road cut on Highway 157 in Lawrence County, Alabama (Site H157, latitude 30[degrees] 24' 38" N, longitude 87[degrees] 49' 51" W; Fig.
describe ultrastructural features of porostromate microproblematica from a Mulde Event (Homerian) bioherm
in Podolia, Western Ukraine, and Vendrasco and Checa illustrate shell microstructure and its inheritance in the calcitic helcionellid Mackinnonia.
The outcrop is exposed in a narrow vertical trench and the geometry of the bioherm
is not entirely visible.
(6) Finally, at the middle Oxfordian, early Transversarium Chronozone the whole platform was homogeneized again and underwent a slow, uniform subsidence, favouring the recovery of subtidal conditions and development of sponge limestone bioherm
and biostrome facies.
Fossils from the Ordovician bioherm
at Meiklejohn Peak, Nevada.
This study examines the sedimentary features of the fossilized calcimicrobes and the development of the microbialitic bioherms
in response to relative sea-level changes within Series 3 Gushan Formation and Furongian Changshan and Fengshan formations.