[1] Pentremites is an extinct genus of blastoid echinoderm belonging to the family Pentremitidae.

[1] These stalked echinoderms averaged a height of about 11 centimetres (4.3 in) but occasionally ranged up to about 3 times that size.

They, like other blastoids, superficially resemble their distant relatives, the crinoids or sea lilies, having a near-identical, planktivorous lifestyle living on the sea floor attached by a stalk.

As with all other blastoids, species of Pentremites trapped food floating in the currents by means of tentacle-like appendages.

[2] Pentremites species lived in the early to middle Carboniferous, from 360.7 to 314.6 Ma.