|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||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||Prosicula characteristically present (pi. 1, fig. 7); metasicula rarely preserved (pi. 1, fig! 3). Corona developed from fourpronged ancora, hemispherical and basket-like, formed of 3-4 rows of gently spiralled lists joined to longitudinally arrayed lists (pi. 1, fig. 5). In specimens with metasicula, "struts" anchor sicula to reticula. First theca develops from clathrial list arising from mouth of sicula; second theca formed from clathrial bar emerging near top of sicula; remaining thecae developing in manner similar to that of Pseudoplegmatograptus. 'Floor' of theca marked by long median list arising from aboral list of previous theca and connected to lip of theca. Lip of theca formed of fine, laterally elongate meshes, divided medially by a zig-zag list. Thecae distinctly orthograptid in profile, with moderately accentuated lips and curved, anterolaterally directed apertures. Reticulum moderately fine, meshwork polygonal, with meshes of more or leass uniform size. Median region of both sides of rhabdosome generally bear large, irregularly shaped, thinwalled stomata, the margins of which stand above the adjacent reticula. Stomata at least twice the size of reticulum mesh-size.|