4 ms·

Fossilization of diatoms doesn't require calcium. Their cell walls are made of silica, which is preserved quite well by itself. Though this is known from Earth

• possibilistic 14y ago
  Assuming such organisms would exist, would we even be able to call them "space diatoms" when there is no established phylogeny? A Panspermia event would likely have seeded our planet with _bacterial_ life; if "space diatoms" exist, they evolved independently of our own. I know there are countless cases of using names and nomenclatures when there is no relation (eg. water bear, sea horse, flying fox, etc.). But we shouldn't call such hypothetical organisms diatoms when they're unrelated. It's in poor form.