Article: New chaetetiform trepostome Bryozoa from the Upper Mississippian of the western United States
Two new bryozoan (ectoproct) genera are part of the fauna of the Late Mississippian carbonate facies in Utah, Idaho, Wyoming, and Montana. Helenopora gen. nov. is widespread and abundant whereas Astralochoma gen. nov. is more restricted and sparse. Gross external features of the bryozoan colonies (size, colony form, and shape of zooecial tubules) resemble chaetetiform colonies. Internal characteristics of the two new genera show them to be bryozoans with distinctive budding patterns. Because of the distinctive features of these two genera, the new families Helenoporidae and Astralochomidae are erected to accommodate them.