Rhombotrypa

Classification
Phylum: Bryozoa
Class: Stenolaemata
Order: Trepostomatida
Family: Amplexoporidae
Genus: Rhombotrypa Ulrich & Bassler, 1904
Cincinnatian Species: Rhombotrypa quadrata, Rhombotrypa subquadrata

[accordions title=”” disabled=”false” active=”1″ autoheight=”false” collapsible=”true”] [accordion title=”Taxonomic Details”]
Type Species: Chaetetes quadratus (Rominger, 1866)
Species found in the Cincinnatian (Bryozoa.net)

Rhombotrypa multitabulata (Utgaard & Perry, 1964)
Rhombotrypa quadrata (Rominger, 1866)
Rhombotrypa subquadrata (Ulrich, 1882)

[/accordion] [/accordions]

Geologic Range
Ordovician – Devonian

Common Paleoecology
Rhombotrypa is an extinct genus of stationary colonial epifaunal filter feeders

Identification in Hand Sample:

Zoarium Morphology: Ramose (large)
Zoecia: Square (or rhombic/quadrate); Thick-walled; No Acanthopores
Mesozooids: Absent
Monticules: N/A
Maculae: N/A

Geographic Occurrences

[accordions title=”” disabled=”false” active=”1″ autoheight=”false” collapsible=”true”] [accordion title=”Published Description”]
Holland (UGA Strat Lab, 2013)

Rhombotrypa is a large ramose form, unique in its square zooecia in the endozone, best seen in a transverse section. Zooecia are thick-walled, with numerous diaphragms in the exozone. Mesozooids and styles are absent.

Fossils of Ohio (1996):

Rhombotrypa Ulrich & Bassler (not illustrated) forms branching colonies. Zooecia in the axial zone have square outlines in branch cross-sections; zooecial apertures are subpolygonal on branch surfaces. There are no small polymorphs or acanthostyles.

Treatise on Invertebrate Paleontology, Part G (1953):

Zooecia of axial region quadrate in section

McFarlan (1931):

Ramose forms with zooecial tubes rhombic or quadrate in cross-section. Acanthopores usually wanting

[/accordion] [/accordions]

R. subquadrata

R. quadrata