Maotian Mountain just doesn’t seem to fit in with its surroundings these days. Set in the high country of southwest China, overlooking the town of Chengjiang, this little peak stands framed against a postcard-perfect lake and terraced tobacco fields that lead up to the tropical sky like some giant staircase. Here in the central Yunnan plateau, spring weather lasts all year long and the air carries a crisp fragrance mercifully free of the pollution that chokes cities to the east.
The small mountain itself, however, is looking a little haggard. Maotian today displays a face pockmarked by gaping pits, heaps of broken stone, and bald patches stripped of vegetation. In the last few years scientists have blasted Maotian with dynamite and hired local peasants to whack at it with shovels; even foreign dignitaries have taken a few cracks at the clay-colored rock. It seems that everyone has an urge to disfigure this unassuming ridge.
The assault on Maotian started in 1984, when Chinese paleontologist Hou Xianguang split open a stone on the west face of the mountain and discovered an unfamiliar egg-size fossil. Although the animal had spent more than a half-billion years entombed in rock, it had weathered the eons so well that Hou could discern its individual limbs, spread out like an army marching in single file; in Hou’s trembling hands this long- dead creature seemed caught in the act of scuttling across the rain-soaked stone. Thus began one of the most important fossil discoveries of the century.
Prospecting around the town of Chengjiang, Hou and other researchers have since uncovered thousands of exquisitely preserved fossils that offer a glimpse back to a pivotal event in the history of life. This moment, right at the start of Earth’s Cambrian Period, some 550 million years ago, marks the evolutionary explosion that filled the seas with the world’s first complex creatures. In a blink of geologic time a planet dominated by simple spongelike animals gave way to one ruled by a vast variety of sophisticated beasts, animals whose relatives still inhabit the world today. This biological big bang reverberated through all facets of existence, altering not only the shape of animals but also the way they lived together. It was at this time that the world’s first predators appeared, an event that forever split life into the hunters and the hunted.
Today, after nine years spent analyzing these fossils, Hou and his colleagues are faced with a startling conclusion. The picture emerging from Chengjiang reveals that the animal kingdom took shape far faster than researchers had previously thought. Life rocketed from primeval to modern in the space of a few million years, an astonishingly short period of time. For paleontologists, the Chengjiang fossils fire the imagination because they offer a chance to understand how this happened. This is Genesis material, gushed one researcher, in reviewing a paper written by Hou and his colleagues.
