Neither the science fiction writer Isaac Asimov, was as rare as this animal had happened. Get the name of Hallucigenia, a marvel of evolution. Its name refers to the word "hallucination", which is what they believed passing the first to see it, as this seems strange prehistoric animal that has been designed by a crazy artist, or an elephant or a dolphin. The paleontologists who discovered not believe what they saw, in fact, did not know its classification; if it was a plant, if it was face up or face down, did not know if he had head and where it was.
They were hallucinated when they found this impossibly small animal that was no more than 4 cm in length and that's apparitions in the Cambrian explosion, when there was the proliferation of life forms, some as strange as this.
As its body is tubular in shape, it is not easy to distinguish, in what place is the head. In fact, experts believe that the head is one of the bulky and ends with two appendices, but it's an assumption that an idea based on a test-out there.
Sensing where the head came next question was: how do walking? And still do not have the solution, after 40 years and several fossilized specimens found. The Hallucigenia had several protrusions. On the one hand, had 7 hard spines, and at first experts thought that moved like sea urchins .... moving the thorns. Then it found that he also had a soft tentacles moving in the opposite area .... how moving it? With the spikes or tentacles? Well, although it seems that the latter is more accepted, do not become totally agree ... and I do not know what to say.I will however get wet at the risk of saying the wrong thing (as you know, ignorance is very bold) If you walk with the tentacles, these could get food and on the other hand, the spines serve them to fend off potential predators. If it walk with barbed tentacles would not do them much good, much less as a defense. Therefore, to put right the Hallucigenia would say his feet were moving tentacles.
With what the story is a bit more complicated.
Anyway, if any of us, or our children, we traveled back in time to the Cambrian; Earth that we know seem another planet in another system, another galaxy and other different physical laws .... at least.