Sea Creatures | smithsonianmag.comhttps://www.smithsonianmag.com/rss/tag/sea-creatures/RSS feed for Sea CreaturesenFri, 10 Jul 2026 16:30:59 +0000An Ancient Sea Once Split North America Down the Middle. The Beautiful Multicolored Ammonite Shells From Its Waters Are So Perfectly Preserved That They Still Shimmer Todayhttps://www.smithsonianmag.com/smithsonian-institution/an-ancient-sea-once-split-north-america-down-the-middle-the-beautiful-multicolored-ammonite-shells-from-its-waters-are-so-perfectly-preserved-that-they-still-shimmer-today-180989104/Spectacular marine fossils tell the story of the long-gone Western Interior Seaway and the planet’s past aquatic lifeFri, 10 Jul 2026 16:30:59 +0000https://www.smithsonianmag.com/smithsonian-institution/an-ancient-sea-once-split-north-america-down-the-middle-the-beautiful-multicolored-ammonite-shells-from-its-waters-are-so-perfectly-preserved-that-they-still-shimmer-today-180989104/