Riley Black

Spectacular marine fossils tell the story of the long-gone Western Interior Seaway and the planet’s past aquatic life South Dakota has no oceanfront. The landlocked state is more than a thousand miles from both the Pacific and the Atlantic, and a rural spot within its borders is regarded as the “continental point of inaccessibility” from the ocean. And yet, signs of the salty water are still there, enclosed in rocks laid down by a long-vanished seaway that once split North America in two.

Pinning down the most titanic of the large sauropod dinosaurs is not an easy task, since the odds were generally against the biggest ones being buried and preserved Nagatitan was immense. The recently announced titanosaur, the largest dinosaur yet uncovered in Thailand, likely stretched more than 88 feet in length and weighed almost 30 tons. The operative word is “likely,” though, because as big as the dinosaur was, only a smattering of its bones made it into the fossil record.

From preserved plants to T. rex, the material found in these Late Cretaceous rocks has resulted in countless breakthroughs for paleontologists In 1902, professional fossil hunter Barnum Brown excavated a stunning set of bones from eastern Montana’s Cretaceous period rocks. The remains were clearly from a large carnivore—far more imposing than the dinosaurs of the earlier Jurassic—but no one had seen a dinosaur quite like this one before.