Fossils

Blood-sucking, disease-spreading ticks are one of the most maligned parasites in the world, and new evidence shows they’ve been doing their dirty work for a long time: Fossilized ticks dating to the mid-Cretaceous represent the first direct evidence that the ancestors of today’s pesky critters once plagued dinosaurs.

Since 2005, a steady trickle of reports detailing proteins and other soft tissues preserved in fossils of dinosaurs and other ancient animals has gradually worn down the disbelief that such tissues can last through geologic time. In a new study in Scientific Reports, scientists have now reported the oldest preserved red blood cells, white blood cells and platelets, found in the remains of an ancient marine reptile.

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.