Below, you see a list with possible ichnogenera for a J- or fan-shaped, unlined, actively filled, (sub)vertical, unbranched burrow. Click on them to get detailed descriptions of the ichnogenus and a list of its ichnospecies. (Please allow for pop-up windows):

• Heimdallia (Ichnogenus usually unbranched, but may be branched)
• Paradictyodora
• Tursia (Ichnogenus includes ornamented ichnospecies)