Monday, January 16, 2012

Escharopora bryozoan from the Verulam fm.

Escharopora is a uncommon bryozoan but I've found many good examples in the Verulam formation in Canada. I've shown a couple of specimens in a prior post but the ones shown below were collected this past fall.

Escharopora tends to form long, thin colonies that are shaped like a sword. This plate of matrix has a very long specimen of Escharopora that is almost 3 inches in length.

The skeleton shows some cracks that likely formed as the sediment was compressed during the dewatering phase.

Here is the growing tip of the colony but the anchor end (a slightly curved point) is missing from the specimen.

Here is a loose specimen that shows the classic sword shape. I'm holding the specimen upside down with the base of the colony (the pointed tip) at the top. The tip would have been attached to the substrate while the rest of the colony projected upward into the currents. I'm not sure if the attachment point was stable or flexible as I can't see any evidence for either scenario.

Another small specimen in matrix with the curved base point present.

The Verulam formation is middle Ordovician in age (Katian/Mohawkian stage) and is found in southern Ontario, Canada.

1 comment:

  1. Hi Dave, Just came back here via a link on TFF, forgot that you had 'my' specimen posted here! Just pointing out that the Katian/Mowhawkian are Upper, not mid Ordov. To your label that came with this I added 'Darriwillian' but I don't remember why?