Coronoidea

According to Dr. Carlton Brett, formost expert on the Rochester Shale, this is not a crinoid or blastoid. He created a new Class, Coronoidea, for these echinoderms (see Brett et al., 1983, Journal of Paleontology). It is similar to a blastoid and although it appears to lack the food grooves and central mouth that a bastoid has, some would make it a subclass of that group. Newer studie support the notion of Coronoidea as a separate class. To date, no true blastoid has been found in the quarry.

Stephanocrinus angulatus Conrad, 1842

1 arm is still buried in the matrix on the right

Possible evidence of corneal regeneration but we can not be sure whether they were really broken and had started to regrow or never really developed equally. Detailed sections of Stephanocrinus show the presence of a small canal that was used for gas exchange.