External mold of Ordovician bivalve showing that the original aragonite shell dissolved on the sea floor, leaving a cemented mold for biological encrustation.
Ordovician bivalves[]
The following 9 pages are in this category, out of 9 total.
- Cuyopsis
- Emiliodonta
- Hemiconcavodonta
- Praenuculidae
- Similodonta
- Solenomorpha
- Trigonoconcha
- Villicumia
- Whiteavesia