Aisenvergiidae

Classification
Phylum: Bryozoa
Class: Stenolaemata
Order: Trepostomatida
Family: Aisenvergiidae (Dunaeva, 1964)
Cincinnatian Genera: Eridotrypa

Geologic Range
Lower Ordovician-Carboniferous

Common Paleoecology
Aisenvergiidae was an extinct family of stationary epifaunal suspension feeders.

Description of the Family

  • Presence of exilazooecia instead of mesozooecia.
  • Characterized by dendritic colonies with tubular zooecia.
  • Budding pattern with long zooecia, larger diameters in the axial part.
  • Dendritic colonies have tubular zooecia.

Published Descriptions

Ernst (2013):

  • Ross (1967) placed the genus Eridotrypa alongside her own genera Lamottopora Ross, 1963 and Newportopora Ross, 1967, in the family Aisenvergiidae Dunaeva, 1964. She argued that these genera have a similar budding pattern with long zooecia having larger diameters in the axial part. The family Aisenvergiidae contained originally three genera: Aisenvergia Dunaeva, 1964, Volnovachia Dunaeva, 1964 and Polycylindricus Boardman, 1960. However, these genera are characterised by completely different wall structure (predominantly merged, without visible zooecial boundaries), and presence of exilazooecia instead of mesozooecia. Therefore, Astrova (1978) criticized the placement of Eridotrypa, Lamottopora and Newportopora in the family Aisenvergiidae.

Ross (1967) :

  • Characterized by dendritic colonies with tubular zooecia whose diameter is reduced in the subperipheral region where zooecial tubes bend and zooecial walls thicken. The earliest representative of the Aisenvergiidae is the Chazyan genus Lamotopora Ross (1963). In addition to the reduced diameter of the zooecial tubes in the subperipheral region, this genus has in the axial region crenulate zooecial walls and zoocial tubes that lack diaphragms; in the well defined peripheral region the zooecial tubes generally lack diaphragms, the mesozooecia have numerous thick diaphragms, and the broad amalgamate zooecial walls have long lamina which are penetrated by distinct acanthopores.
  • Dendritic colonies have tubular zooecia which are polygonal in cross section in the axial region. Zooecia form an elbow-shaped bend near the periphery and are greatly reduced in diameter in the subperipheral region;
    occasionally the zooecial tubes are completely constricted so that in transverse section, a circular line marking the region of constriction divided the axial and peripheral regions. Acanthopores and mesozoocia are generally present in varying numbers but they are absent (After Dunaeva, 1964).

Eridotrypa