 The continuing search for Burgess Shale fossils since the mid @-@ 1970s has led to the description in the 1980s of an arthropod Sanctacaris and in 2007 of Orthrozanclus , which looked like a slug with a small shell at the front , chain mail over the back and long , curved spines round the edges . Recent digs have discovered species yet to be formally described and named . They have also unearthed more and sometimes better fossils of animals that were discovered earlier , for example Odontogriphus was for many years known from just one poorly preserved specimen , but the discovery of a further 189 formed the basis for a detailed description and analysis in 2006 . Re @-@ examination of Walcott 's collection also continues , and has led to the reconstruction of the large marine animal Hurdia in 2009 . 
