She sells sea scorpions by the sea shore

Way back about a half billion years ago, sea scorpions were one of the top predators in the oceans. Apparently they could come out of the water too, although by the time the tracks the article mentions were made, amphibeans were already on the scene there, and fish were taking over the big roles in the oceans. (The sea scorpions were extinct about 50 million years after this fossil was laid.) The fossil also shows why you don't see giant ants or spiders: the five-foot-long animal that left it had to crawl, since it wasn't strong enough to actually stand without water supporting its weight. Everybody's reporting this as a 'water scorpion', by the way, which is incorrect -- water scorpions are insects, which aren't descended from the sea scorpions. (Imagine Arthropoda as a big family: Water scorpions would be like the descendents of the sea scorpion's cousins. True scorpions would be like the sea scorpion's siblings and their kids.)

Speaking of long-dead animals, it looks like the feet of Archaeopteryx were built like a dinosaur's. Birds have the first toe pointing backwards. Dinosaurs had the first toe pointed forwards. This is neat because it gives us a more precise idea of how feathered non-avian dinosaurs evolved into birds. (I worded that strangely on purpose; technically modern birds are a sub-group of the coelurosaurs. So are the tyrannosaurs, though there's probably not a direct descent.) It also gives us a bit more evidence of how evolution happens: the fewer avian features we find in early protobirds, the more steps it took as a process. Dinosaurs did not just jump straight to birds; there were intermediate steps. So I think it's interesting.