Early Ordovician – Late Devonian
Tentaculitida is an extinct order stationary semi-infaunal suspension feeders.
Characteristics of the Class
- Usually 15 to 30 mm in length.
- Conical embryonal chamber with blunt, pointed apex.
- laminate shell walls with 2-5 layers.
- Shell septate, with multiple chambers distinct from large apertural cavity.
Treatise on Invertebrate Paleontology, Part W, Vol. 1 (1962):
- Cricoconarids with conical embryonal chamber terminating in a blunt pointed apex. Length, 1 to 80 mm., usually 15 to 30 mm.; shell wall thick or thin, with tiny radial canals piercing thick-walled forms; shell wall laminate, usually 2 to 5 layers. Juvenile portion of shell septate, forming several chambers distinct from large apertural cavity. Exterior covered by transverse rings of various size and spacing. Longitudinal striae rarely present. Interior wall surface ringed or smooth. About 110 species have been described.