Fig. 2
From: Progress and perspectives in the discovery of polychaete worms (Annelida) of the world
a The number of species described per year. b The number of first authors per year. c The number of species described per first author per year. The black lines are six-year moving average. The red linear correlation line represents the best fit based on the piecewise regression analysis (Additional file 1: Figure S2), showing that there is a statistically significant trend of decreasing number of species per author since around mid-nineteenth century (prior to that, there is not enough evidence to identify a trend)