New details about ancient creature give hints to evolution of some animals’ teeth
Whether it’s upside down or right side up, Hallucigenia sparsa looks like it wriggled right out of a nightmare. And giving the wormlike creepy-crawly a head hasn’t helped.
An analysis of 508-million-year-old H. sparsa fossils from the Burgess Shale in Canada revealed that the 10- to 50-millimeter-long critter had a small pair of simple eyes set atop a narrow head. Below the head was a long neck that protruded from a tubular body sporting 10 sets of dangly appendages and seven pairs of spines. Platelike structures