Tentaculoida

Tentaculoida is an extinct class of marine animals belonging to the phylum Tentaculocoelenterata. Fossil evidence suggests these creatures lived during the Cambrian period, approximately 541 to 485.4 million years ago. The defining characteristic of Tentaculoida was the presence of a ring of tentacle-like appendages surrounding the mouth. These tentacles were likely used for capturing small prey or filtering food particles from the water.

Tentaculoida are thought to have possessed a soft, unsegmented body. Some fossil specimens exhibit a casing or shell-like structure, though its precise composition and function remain subjects of scientific debate. Their overall morphology suggests a sessile or semi-sessile lifestyle, attached to the seafloor or other substrates. The exact phylogenetic relationships of Tentaculoida are not fully understood, but they are often grouped with other early complex organisms from the Cambrian explosion. The class appears to have gone extinct by the end of the Cambrian, with no known descendants surviving into later geological periods. The limited fossil record makes detailed study challenging, but ongoing research continues to shed light on these ancient marine invertebrates.