Requiem for ancient tongue worm: New species of intruder discovered

Researchers have discovered the 425-million-year-old fossil remains of a new species of parasite, still attached to the host animal it invaded long ago. The new species is a type of tongue worm, an arthropod that has a worm-like body, a head, and two pairs of limbs. Its modern-day relatives live within the respiratory system of host animals, sometimes even humans, after being ingested via an intermediate host such as a fish. An international team of researchers found several specimens of the new species, named Invavita piratica (meaning "ancient intruder" and "piracy"), in 425-million-year-old rocks in Herefordshire, England. The specimens were "exceptionally well-preserved," according to the researchers, and range in size from about 1 to 4 millimeters long. A study describing the ancient parasite appears in the May 21 edition of the journal Current Biology. "This is the most important fossil evidence yet discovered of the origins of this type of parasitism," said Yale University paleontologist Derek Briggs, co-author of the study. Briggs is the G. Evelyn Hutchinson Professor of Geology and Geophysics at Yale and curator of invertebrate paleontology at the Yale Peabody Museum of Natural History. This is the first fossil tongue worm species to be found associated with its host. In this case, the host is an ostracod—a group of micro-arthropods with two shells that are joined at a hinge.READ MORE -http://phys.org/news/2015-05-requiem-ancient-tongue-worm.html