The tiny sea creatures changed shape using a spiraling arrangement of five ambulacra, or grooves coming from the mouth that opened and closed to capture bits of food floating in the water.
The newly discovered species is the oldest known echinoderm with five ambulacra, and could shed light on how echinoderms evolved their unique body plans, Smith said.
H. moroccoensis was also found in sediments containing several other bizarre echinoderms, many of which had wacky body plans, ranging from completely asymmetrical to bilaterally symmetrical. That wide variety suggests the creatures were going through a period of dramatic diversification around that time period, Smith said.
"The important thing about the whole fauna is that there is already, by this time, a remarkable diversity in body form," Smith said. "And yet this is only 10 (million) to 15 million years after the calcite skeleton evolved."
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