Attachment loops on infant brachiopods from the Louisiana limestone in Missouri
Athel Glyde Unklesbay, and Walter B. Niewoehner
Shaly partings in the Louisiana limestone in northeastern Missouri contain many small brachiopods. Some of these have been described as Strophalosia and Leptalosia. Recently discovered ones, however, appear to belong to neither of these genera but are infantile representatives of the genus Productella. The pedicle valve of these minute forms bears a loop formed by the upward curving growth of a pair of spines on opposite sides of a shallow median groove. This loop was apparently used in infant stages as a means of attachment to the spines of adults or to the spines and stems of crinoids. Although larger specimens of Productella are spinose, the attachment loops are not present on those larger than 10 mm. in width.
This record provided courtesy of AGI/GeoRef.
