Pentremites are an extinct genus of stemmed echinoderms, members of the genus that includes starfish and sea urchins. These blastoids were connected to the seafloors by long stalks, and would have fed itself through filters inside this fossilized bud.
 
Weight of entire piece: 4 g
 
Measurements: 1" x .5"
 
Time Period: early to middle-Carboniferous period