Fossilized Eggs in a Pennsylvanian Blastoid

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Science  11 Jun 1976:
Vol. 192, Issue 4244, pp. 1137-1139
DOI: 10.1126/science.192.4244.1137


A single specimen of Pentremites rusticus (Echinodermata, Blastoidea) from the Early Pennsylvanian of Oklahoma has hundreds of apparent eggs in one of its abnormal anal hydrospire groups. This rare occurrence suggests that female blastoids in this sexually dimorphic species had modified their anal hydrospiresfor brooding eggs instead of for normal respiration.