Fossils

Canada’s Burgess Shale is famous for a wide array of exquisitely preserved 500-million-year-old fossils, which are found in a dozen localities in the Canadian Rockies. Linking all these localities today is a geologic feature called the Cathedral Escarpment, which formed in the Cambrian as a steep line of underwater cliffs where regular mudslides are thought to have gently buried a diversity of organisms, setting the stage for the prolific fossil beds. However, new mineralogical clues found at several of the fossil-rich sites suggest that mud volcanism may have also played a starring role in creating the Burgess Shale.

Off the coast of Texas, a collection of fossil coral reefs sits under 60 meters of water — relics from 20,000 years ago, when the sea surface was much lower than today. In a new study, researchers created high-resolution maps of the reefs that suggest they drowned as sea levels rose in rapid bursts — each lasting decades to centuries — instead of at a steady rate, as has long been assumed.

Threats to species can encourage evolution, leading to animals with harder shells or other defensive adaptations. In a recent study in the Journal of Systematic Palaeontology, researchers found that while some ancient brittle stars — relatives of starfish with long, whip-like arms — evolved in the face of threats, some adapted a different approach: they moved.

Fossilized feces tell paleontologists a lot about what dinosaurs ate. Some unusual coprolites discovered in Utah’s Grand Staircase-Escalante National Monument may indicate that normally herbivorous dinosaurs occasionally ate crustaceans.