Experts analyzed 170 trace fossils from millions of years before the Cambrian Period and assert that advanced features may have been a reality before the explosion.

"Cambrian Explosion: New timeline for appearances of skeletal animals in fossil record." ScienceDaily. ScienceDaily, 10 November 2010. <www.sciencedaily.com / releases / 2010 / 11 / 101110091115.htm>.

Meanwhile, authors revised the Cambrian chronostratigraphy of China and proposed a new Xiaotanian Stage for the Cambrian Stage 2 of China. In addition, ...