Worm monstrosity: A giant extinct worm

Mats E Eriksson (Sweden) In a new study published in Scientific Reports (Earth’s oldest ‘Bobbit worm’ – gigantism in a Devonian eunicidan polychaete) by Luke A Parry of Bristol University in the UK, David M Rudkin of the Royal Ontario Museum in Canada and me (Mats E Eriksson of Lund University in Sweden), an extraordinary new species of polychaetes (that is, bristle worms – the marine relatives of earthworms and leeches) is described. The new species, Websteroprion armstrongi, is unique among fossil worms and possessed the largest jaws recorded from all of earth history, reaching over one centimetre in length and thus easily visible to the naked eye. Typically, such fossil jaws are only a few millimetres in size and must be studied using microscopes. Despite being only knows from the jaws, comparison of Websteroprion armstrongi with living species suggests that this animal achieved a body length in excess of a metre. This is comparable to that of ‘giant eunicid’ species, colloquially referred to as ‘Bobbit worms’, a name that is bizarrely enough derived from the infamous story of eye-watering amateur surgery involving Lorena and John Wayne Bobbitt. Living ‘Bobbit worms’ are fearsome and opportunistic ambush predators, using their powerful jaws to capture prey, such as fish and cephalopods (squids and octopuses), and drag them into their burrows. Fig. 1. A photograph showing the holotype of Websteroprion armstrongi. (Photo by Luke Parry.) Gigantism in animals is an alluring and ecologically important trait, usually associated with advantages and competitive dominance. It … Read More