What fossils reveal about the spider family tree is far from horrifying | Susannah Lydon

Recent fossils in amber tell us how spiders evolved into their modern groups, but the fossil record for arachnids goes much deeper

The discovery of a 100m-year-old spider ancestor with a whip-like tail, bearing a more than slight resemblance to everyone's favourite parasitoid alien - the facehugger - gained a lot of media interest last week. Some arachnologists were upset by both the language of fear in the coverage ("creepy" and "horrifying" were popular descriptions) and by some folks expressing a desire to nuke it from orbit. It seems that despite (or perhaps because) of the intense responses that spiders evoke in people, there is always an interest in where and how they evolved.

The newly described species, Chimerarachne yingi, was based on two specimens found in amber of about 100 My old from Myanmar. Unusually, the new find was revealed in two simultaneously-published papers in the journal Nature Ecology & Evolution. The rules for the naming of species mean that only one of the papers, by Bo Wang and colleagues, gets to be the formal description and naming of the species (and new genus, the next level up in classifying organisms). Both Wang's paper and that of Diying Huang and colleagues, aimed to place the new find in terms of the spider family tree. The new species has features of modern spiders, known as the Araneae: a male pedipalp (sensory appendage) modified for sperm transfer, and well-defined spinnerets for silk spinning. But, it also has its distinctive tail, a feature not found in modern spiders, but associated with an ancient grouping of "almost-spiders" known as the Uraraneida.