- seed with 3 (or sometime 6) ribs around
- in compressed specimens from the coal layers mostly 1 or 2 ribs are visible
The seeds are attributed to Alethopteris and Neuropteris. We have found only a few of them. This agrees with the fact that we didn't find (convincing) leaf fossils of these two groups, though they might occur. The seeds had originally a more soft covering, but this is always vanished.
Height of the photo 3 cm.