|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||Age range and collections|
Pterobranchia - Bireclinata - Retiolitidae
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|A. C. Lenz and M. J. Melchin 1987||Corona rounded, width nearly equal to maximum width of rhabdosome which is attained at the level of the first theca, composed of a few irregular clathrial lists. Coronal meshwork made finer through addition of reticular lists, but maintains two large, adjacent basal-lateral pores. Rhabdosome of most specimens narrow rapidly distally and thecae generally number 3-4 per side. Clathrial pattern complex and irregular; reticulum well developed, relatively fine, list widths becoming coarser with maturity. Thecae long, outer margins undulose (pi. 2, figs. 13,14), overall rather similar in profile to those of Pseudoglyptograptus, apertures generally horizontal. Meshwork of tubular appendix finer than that of more proximal regions. Virgula moves to ventral side early in development, but becomes attached to, and incorporated in, ventral wall about two-thirds along length of typical rhabdosome, then joined by alternating left and right bars for remainder of length; extends beyond rhabdosome. Seams of clathrium face in, and those of reticulum face out.|