Blastoid

About it

Small, bud-shaped echinoderms with five petal-like food grooves, about the size of a hazelnut. Pentremites is common in Mississippian rocks of Illinois, Kentucky, Indiana, and Alabama; Permian ones come from Timor.

Type

Fossil (echinoderm)

Group

Blastoid (echinoderm)

Colours

grey, brown, tan, white

Transparency

opaque

Periods

Devonian, Carboniferous, Permian

Typical values: real specimens vary. For more, see mindat.org.