Spiny, armored slug reveals ancestry of molluscs

Date: February 6, 2017

Source: University of Bristol

Scientists from the University of Bristol have uncovered a 480-million-year-old slug-like fossil in Morocco which sheds new light on the evolution of molluscs -- a diverse group of invertebrates that includes clams, snails and squids.

One of the defining characteristics of the molluscs is the possession of a radula, a kind of toothed-tongue which is used to rake up or rasp food.

The radula houses hundreds of teeth, the patterns of which can be used to determine diet and identify species. Whilst not all molluscs have a radula, a radula cannot be found in any other group of animals. Dr Jakob Vinther, from the Schools of Biological Sciences and Earth Sciences, is lead author of the study, which is published today in Nature.

He said: "The molluscs are amongst the earliest animals identifiable in the fossil record, however determining what their ancestor looked like is difficult since many of the groups appear within a small window of time, making the sequence of evolutionary events difficult to piece together."

The recent discovery of a new species of mollusc in the Anti-Atlas region in Morocco has enabled palaeontologists to revisit this problem and infer the appearance of the ancestor of all molluscs.

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The Monstrous Super Slug Causing Car Crashes, Devaluing Homes - And Invading Tyne And Wear

A monstrous mollusc known as the Spanish ‘super slug’ is invading the North East, Newcastle University experts warned.

And it is believed the recent warm, wet weather has encouraged it to multiply rapidly.

Growing to more than 10cm in length, the carnivorous Spanish Slug far outweighs its English cousin and can produce hundreds more eggs, enabling it to reproduce at a far quicker rate.

The gigantic slugs are already a problem in other European countries such as Norway and have been known to reduce house prices in areas where the creatures are found.

Dr Gordon Port, lecturer at Newcastle University, researching environmentally friendly pest control, said: “The Spanish Slug seems to be very good at rapidly invading areas.

“One possible explanation for that is having come from a hot climate where a lot of the young slugs might die due to drought and heat, coming to a nice wet country, it’s actually thriving terrifically.

“Too many slugs can cause problems, not just for gardeners. In Austria, they have had incidents of car accidents because the numbers have built up on the road and formed this horrible slimy slick and cars have skidded off.”

http://tyneandwear.sky.com/news/article/24676