This leggy , spiny fella isDouglassarachne acanthopoda , whom we ’ll call Doug for short ( only kid ) . You might count at this ossified specimen and confidently declare , “ That there ’s a wanderer . ” But wait ! WhileD. acanthopodacertainly share many of the characteristic of modern arachnoid , it has enough unique features to give palaentologists a headache when it comes to classifying it .
Spiders and their ancestor have been around on this satellite for about the last400 million years . If you were thrust back in time to the Carboniferous and bring down in the coal timber of North America or Europe , you ’d likely see some critter you ’d recognize asspiders , harvestmen , or scorpions . But even among that pack , D. acanthopodawould have stood out .
“ Douglassarachne acanthopodacomes from the famous Mazon Creek locality in Illinois and is about 308 million years old , ” state Paul Selden , lead writer of a new written report on this enigmatic fogey , in astatement . “ This compact arachnid had a body length of about 1.5 centimeters [ 0.6 inch ] and is qualify by its remarkably full-bodied and spiny leg – such that it is quite unlike any other arachnid known , bread and butter or out . ”
This reconstruction shows how the 308-million-year-old may have looked in its heyday.Image credit: Paul Selden et al.
So unlike , in fact , that Selden and cobalt - author Jason Dunlop were drive to reason that it but does n’t fit into any of our known orders of arachnids .
“ The fogey ’s very setaceous leg are reminiscent of some forward-looking harvestmen , but its body plan is quite different from a harvestman or any other known arachnid group , ” Dunlop explained .
Being over 300 million years old , it ’s graspable that the dodo is missing a few details , like clear mouthpart , which could help narrow down an appropriate categorisation . This period of our planet ’s history is suppose to have been the first when most living mathematical group of arachnids range around together , and the Mazon Creek location – whereD. acanthopodawas found in the 1980s – is one of our most important portal vein to this time .
“ Whatever its evolutionary affinities , these briery arachnoid appear to come from a fourth dimension when arachnids were experimenting with a mountain chain of unlike body plans , ” Selden said . “ Some of these after became nonextant , perhaps during the so - call ‘ Carboniferous Rainforest Collapse , ’ a time curtly after the age of Mazon Creek when the ember forests began to fragment and pall off . Or perhaps these unusual arachnids clung on until the end Permianmass extinction ? ”
The fogy spent some old age on video display in the Prehistoric Life Museum as part of the David and Sandra Douglass Collection . And although this exceptional critter is proving tricky to separate , it did still want ascientific name .
“ The genus nameDouglassarachneacknowledges the Douglass family , who kindly donated the specimen to the Field Museum of Natural History in Chicago for scientific field of study once it became ostensible that it lay out an undescribed coinage . Then , acanthopodarefers to the unique and characteristic spiny legs of the animal , ” sound out Dunlop .
In some places on our satellite today , you almost feel that youcan’t escapefrom spiders , no matter how hard you seek ( pagingAustralia).New species , and somewe thought we ’d lost , are popping up all over the shop .
But back in the daytime , Dunlop explain , “ spider were a rather rare group . ” Their ancestors would have shared the globe point with many telling beasties that have long since been lose to us , withfossilsour only chance now to divulge their many - legged diverseness .
And for Dunlop , “ Douglassarachne acanthopodais a specially impressive example of one of these out chassis . ”
The work is published in theJournal of Paleontology .
