Quaestio simpsonorum is part of the Ediacara Biota, which preserves the oldest evidence for complex, macroscopic animals. Close up of Quaestio simpsonorum footprint. Image credit: Evans et al., doi: 10.1111/ede.12491. Quaestio simpsonorum is one of more than 100 multicellular organisms from the Ediacaran period (635 to 538 million years ago), when the first complex, macroscopic animals emerged on Earth. This creature was up to 8 cm (3.1 inches) wide...
