A tiny marine animal that was thought to be extinct for the past four million years has just been found living in New Zealand.
This “living fossil” is tentacled polyp called Protulophila, and they were previously only found in fossil deposits in the northern hemisphere, specifically Europe and the Middle East. Scientists think their history extended back 170 million years into the Middle Jurassic, before they went extinct in the Pliocene; the last trace of them were found in four-million-year-old rocks. Paleontologists think that Protulophila was a colonial hydroid (resembling a hydra) that’s related to corals and sea anemones. The animal formed a network of channels and microscopic holes inside the chalky tubes of marine worms called serpulids.
This year, fossil examples were discovered by researchers from New Zealand’s National Institute of Water and Atmospheric Research in Australia, London’s Natural History Museum, and the University of Oslo as they were conducting fieldwork at Wanganui on the west coast of North Island.
They found fossil evidence of tiny Protulophila polyps in a network of holes in a worm tube from young rocks (geologically speaking) that are less than a million years old. Pictured above, a scanning electron microscope (SEM) image of a resin cast of the polyp chambers and connections of Protulophila in a worm tube.
After finding Protulophila in young rocks in the southern hemisphere, the team examined tubeworms stored in NIWA’s collection and found examples of preserved Protulophila that had been overlooked. These samples were collected in 2008 in about 20 meters of water near the town of Picton on the northeast corner of South Island. Here's an artist’s impression of living Protulophila polyps with tentacles protruding from openings in a worm tube.
“Our detective work has also suggested the possibility that Protulophila may be the missing polyp stage of a hydroid in which only the tiny planktonic jellyfish stage is known,” NIWA’s Dennis Gordon says in a news release. “Many hydroid species have a two-stage life cycle and often the two stages have never been matched. Our discovery may thus mean that we are solving two puzzles at once.”
The team is hoping to collect fresh samples from Queen Charlotte Sound near Picton for gene sequencing.
Images: Paul Taylor, Natural History Museum, London (top, middle) & Dennis Gordon and Erika MacKay, NIWA (illustration)