Board Thread:Fiction Universe Discussion/@comment-47205-20160329150225/@comment-1073312-20160409001210

I'm not sure how these super-spirals form, but yes, the dynamic like ours: galaxies feeding upon galaxies. The current lower limits for the Milky Way's age has been estimated to be between something like 12.7 and 13.8 billion years by measuring abundances of radioactive elements in stars, so it;s likely our galaxy formed at the same time as these monsters but took a very different evolution.

If we do set the Super Spiral galaxy to be the past, I agree, all of those suggestions are possible. Perhaps more galaxies survived the Annihilation (or that they were explored pre-Annihilation), but that's something that might be best left open for now.