Cladistic analysis of the arachnids showing the position of Idmonarachne brasieri gen. et sp. nov.

Almost a Spider

Scientists have finally placed this 305-million-year-old fossil arachnid

This might not be a missing link per se, being an extinct sister group. How fantastic that they can describe an extinct taxon by comparing a 305-million-year-old fossil to other fossils and present-day arachnid morphology!