Fig. 1.

Collection dates for 200 randomly selected land snail species. Collection dates, recorded from the literature, museum collections, and consultation with experts for 200 randomly selected land snail species, ordered by date of last collection. Each horizontal line represents all of the collection dates for a single species from 1786 until 2012. Open circles (○; top line) represent all collection dates of mollusks (i.e., proxy for sampling effort). Note the large proportion of species known only from the original collection (e.g., most species between lines 150 and 200).