Phylum: Bryozoa
Class: Stenolaemata
Order: Trepostomatida (Ulrich, 1882)
Cincinnatian Families: Aisenvergiidae, Amplexoporidae, Atactotoechidae, Batostomellidae, Halloporidae, Heterotrypidae, Mesotrypidae, Monticuliporidae, Trematoporidae, Unassigned Genera

Geologic Range
Early Ordovician – Late Triassic (or Recent?)

Common Paleoecology
Trepostomida is an extinct order of stationary epifaunal suspension feeders

Characteristics of the Order

  • Zoaria usually massive, lamellate, or stemlike
  • Autozooids containing basal diaphragms and commonly other lateral structures
  • Zooecia consist of long calcareous tubes, generally intersected by many partitions
  • Kenozooids common, extrazooidal skeleton in some

Published Descriptions (2013)

  • Colonies encrusting or erect; autozooids generally containing basal diaphragms and commonly other lateral structures; kenozooids common, extrazooidal skeleton in some; skeletons without communication pores, typically laminated. Lower Ordovician to Upper Triassic (or Recent?).

Elias & Condra (1957):

  • All Cryptostomata were originally classified in comprehensive suborder Cyclostomata (Ulrich, 1882, p. 149-151). In 1883 Vine removed from Cyclostomata the bifoliate and a few closely allied ramose forms were the last removed from Cyclostomata. The fact that they possess zoarial plexus, apparently homologous to the common bud of Cyclostomata, and the fact that comparable structures are absent in other Cryptostomata suggest a return to Vine’s concept of Cryptostomata and segregation of fenestrate forms into the new order Fenestrata to be added to Borg’s class Stenolaemata at a par with orders Trepostomata and Cyclostomata.

Treatise on Invertebrate Paleontology, Part G (1953)

  • Zoaria mostly massive, lamellate, or stemlike, comprising typical so-called stony bryozoans. Zooecia consist of long calcareous tubes, generally intersected by many partitions (diaphragms), each tube being divisible into an immature region in the axial part of the zoarium characterized by thin walls, wide spacing of diaphragms, and contact with other zooecia on all sides, and a mature region near the zoarial surface characterized by thickened walls, close spacing of diaphragms, and intervention of special cells (mesopores, acanthopores) between zooecia. Monticules or maculae, comprising regularly spaced clusters of cells smaller or larger than average, commonly well defined on zoarial surface.










Unassigned Genera