Researchers have discovered remains of a newly discovered species of parasite, which is 425-million-year-old, still fixed on the host animal it attacked. The fossil has been discovered by the international team at a site in Herefordshire in the Welsh borders. In order to study deeply, Prof. David Siveter from the University of Leicester and his colleagues made digital ‘virtual fossil’ by scanning layers of the limestone, in which it was embedded.

He spoke on the importance of the discovery, and also described the importance of site for scientists. He was speaking to the BBC whilst on a field trip in Japan. The fossil has been discovered in England; it is a 425-million-year old tongue worm. It is a prehistoric parasitic intruder, found clamped to the host animal it invaded; it lived in its respiratory system.

The tongue worm had a body similar to a worm as it had two pairs of limbs and a head. The parasite lived in the respiratory system of the host; it entered the respiratory system when it was eaten.

The fossil was discovered by Siveter, who works at the Department of Geology at the University of Leicester, together with scientists from the University of Oxford, Imperial College London both in the UK, and Yale University in the US.

Findings of the study have been published in the academic journal Current Biology. The Yale Peabody Museum of Natural History, the John Fell Oxford University Press (OUP) Research Fund, The Natural Environmental Research Council, and the Leverhulme Trust supported the study.

According to Siveter, “This discovery is important not only because examples of parasites are exceptionally rare in the fossil record, but also because the possible host of fossil tongue worms – and the origin of the lifestyle of tongue worms – has been the subject of much debate”.