In “Cambrian Shutter of Doom Becomes Sucker of Worms” (Wired Science, “Laelaps” May 15, 2012), Brian Switek offers us a look ar the reconstructed Cambrian creature, Anomalocaris:
Not all anomalocaridids had identical mouthparts, though. Peytoia and Hurdia had the classic four-part mouth shape, and Hurdia, in particular, possessed an extra array of small spines in the middle of its mouth. Clearly these animals were feeding on disparate prey and doing so in different ways – a conclusion supported by the variations in the spiny frontage appendages anomalocaridids used to grasp prey. “As opposed to being highly specialized trilobite predators, anomalocaridids were generalists occupying a range of ecological habits, from freeswimming ambush predators to sediment-sifting scavengers,” Daly and Bergström concluded. We’re only just starting to understand the ecology and biology of these absolutely fantastic animals. In this case, strange mouths hint that the celebrated idea of an intense Cambrian arms race between shutter-mouthed predators and trilobites was not as intense or dramatic as we thought.
Some Cambrian animals really do sound like science fiction. No guys, they didn’t invent science fiction. It’s convergent evolution.