Hundreds of fossils uncovered in southern China's province of Yunnan reveal that at least some of the life-forms scientists had thought arose in the Cambrian period were alive and thriving millions of years earlier, in an era known as the Ediacaran period.
The mirror spider can rapidly shift a patchwork of minuscule reflective plates underneath its abdomen's outer surface, altering the pattern of mirrorlike flashes. This uncommon display comes from common building blocks: Similar tilelike arrangements of plates and soft joints appear throughout the tree of life, from turtle shells to tropical fruit peels. Researchers have now compiled 100 examples of this pattern across animals, plants, microbes and viruses, which they describe in PNAS Nexus.
The study's authors researched 96 peer-reviewed studies documenting SSB to compile one of the most comprehensive datasets for primates to date. The study found that SSB are a "persistent and integral component of primate social [practices]." In fact, the prevalence of SSB across a variety of closely related primate species - and over several lines of descendants - "indicates a deep evolutionary root or multiple independent evolutionary origins," the study's authors wrote.
Wooden objects carrying the marks of carving and use could be the oldest wooden tools ever found. Researchers dated the artefacts, found in what is now Greece, to 430,000 years ago - and suggest they might have been made by early Neanderthals or their ancestors, Homo heidelbergensis. A separate study describes 480,000-old flint-knapping tools made from antler and elephant bone, from what is now the United Kingdom.
Which animals came first? For more than a century, most evidence suggested that sponges, immobile filter-feeders that lack muscles, neurons and other specialized tissues, were the first animal lineages to emerge. Then, in 2008, a genomic study pointed to a head-scratching rival: dazzling, translucent predators called comb jellies, or ctenophores, with nerves, muscles and other sophisticated features. That single study ignited a debate that has raged for nearly 20 years, sparking fierce arguments about how complexity evolved in animals.
The lava heron also has a much thicker bill than other closely related herons - an adaptation linked to feeding among sharp volcanic rocks and hard-shelled prey. "What we learned was something that hadn't been reported before," Mendales said. The discovery underscores how much remains unknown, even in iconic places like the Galápagos, said John Dumbacher, the Academy's curator of birds and mammals and Mendales' thesis adviser.
