Phylum: Mollusca
Class: Tentaculita (Boucek, 1964)
Cincinnatian Families: Cornulitidae, Tentaculitidae

Geologic RangeResponsive Pro Options
Cambrian – Carboniferous

Common Paleoecology
Tentaculita is an extinct class of stationary semi-infaunal suspension feeders

Characteristics of the Class

  • Currently defined as a Mollusk, however this is not definite
  • Cones vary from several millimeters to several centimeters in length
  • Tri-layered shells with conical shape and round or polyhedral cross sections
  • Pseudopuncta and septa sometimes present

Published Descriptions

Farsan (2005):

  • Tentaculitids with a calcareous cone that varies from several millimeters to several centimeters in size, with a conical shape and round or polyhedral cross section in post-larval stages. The primary shell is composed of three layers consisting of the initial, subsequent and final layers. The early ontogenic parts have two different modes of construction (Fig. 14): The first begins with differentiated larval parts, closed at the apical end, showing a distinct biologic metamorphosis; alternately, the cone passes through an embryonic stage with no obvious postembryonic differentiation. Transverse or/and longitudinal sculpture are present, and secondary shell, pseudopuncta and septa are sometimes present. Microstructure of the shell is lamellar, sigmoidal or nacreous

Boucek (1964)

  • An extinct palaeozoic class of marine organism with small (from a fraction of 1mm to 80mm) calcareous shell-tube. The tubes are usually straight, but sometimes slightly curve, or in some cases they are attached to foreign bodies-even irregular or deformed. Cross-section circular, thus symmetry being generally radial. Aperture diagonal, as wide as the tubes, without operculum. Mostly vagrant benthic, nektobenthic or plantonic-pelagic, sometimes sessile, attached to the substrate or some foreign shells.