Description

Trigonocarpus sp.
Seed
Middle Pennsylvanian (Desmoinesian)
Savanna Formation
Macintosh County, Oklahoma, USA

Huge 155mm matrix block with two giant 40mm pteridosperm seeds.

Carboniferous. Plant.

Trigonocarpus is a form-genus for a seed type produced by members of the plant order, Medullosales.  These seeds, distinguishable by their three-ridged shape, grew into small trees that thrived in the “coal swamps” (flooded forests that became buried and transformed over a couple of hundred millions of years into the vast coal deposits of the eastern U.S. and Europe).  These plants survived into the Permian but died out before the end of the period as a result of climates trending warmer and drier.

Great matrix piece with two well-preserved and truly ancient seeds.