Enlarge (credit: Majkic et al. 2018) At first glance, it doesn’t look like much: a few uneven lines etched into the soft, chalky outer layer of a small, thin flint flake. But a group of archaeologists claims those uneven lines are a deliberate marking, making the 3.5cm-long flake the latest piece of evidence for symbolic thought among Neanderthals. Kiik-Koba Cave overlooks the Zuya River in the Crimean Mountains.