The horseshoe crabs (Xiphosura) are a group of large aquatic arthropods known from the East coast of the USA, and the Southern and Eastern coasts of Asia. Despite their name, they are not actually crabs at all, but are chelicerates (the group containing spiders and scorpions). As a group, the horseshoe crabs possess an extremely long fossil record, reaching as far back as the Ordovician Period, some 480 million years ago. Since that time, they would appear to have undergone very little change, leading the horseshoe crabs to become the archetypal 'living fossils'.

Joining us for this two-part episode is Dr Russell Bicknell, University of New England, Australia. We discuss what makes a horseshoe crab, before taking questions from our listeners as to all aspects of horseshoe crab ecology and what we can infer from them about other extinct arthropods.

With palaeontology as popular as it is you will never be short of content online, whether that be articles, blogs, podcasts (of which there are now many others you should also be listening to) or videos. This allows you, the public, to enjoy learning about past life on demand and in a format that best suits you. The only issue with having so many sources of information/entertainment is that the quality can be highly variable and it can be difficult to determine whether any given outlet/channel values more the accurate communication of palaeontological science or the number of viewers/ad revenue they get.

Amongst some notable exceptions to this issue is the YouTube channel PBS Eons, who have produced a hugely successful series that also stands up to scientific scrutiny. In this interview, we're joined by Eons host Kallie Moore who discusses everything to do with the show, from how it is researched and shot, to the benefits of using YouTube for outreach.