FIGURE 1. Numbers of published articles in Palaeontologia Electronica, per year (2017 exclusive). This graph was drawn using PAST ver. 2.17c (Hammer et al. 2001).

FIGURE 2. Research articles published in Palaeontologia Electronica for each year (2017 exclusive), expressed as a percentage of each article category. Over the years PE has published research articles in a number of sub-categories: a Critical Review category was used briefly, Technical Articles have been differentiated from Research Articles since 2009, and the Fossil Calibration Articles were introduced in 2015. However, for consistency and in order to examine our 20 year trends, I have gone back through all research articles and retroactively assigned each to one of five categories: Research, Technical, Taxonomic, Review/Atlas/Guide, and Fossil Calibration.

FIGURE 3. Research articles published in Palaeontologia Electronica for each year (2017 exclusive), expressed as a percentage of each palaeontological sub-discipline. This represents a somewhat more arbitrary (compared to Figure 2) assignment of each research article to one of 11 palaeontological sub-disciplines. This assignment is more arbitrary because many articles aren’t easily categorised into a single sub-discipline and, depending on subject matter, the sub-disciplines themselves can overlap. Other articles, particularly highly technical articles, don’t always fit so neatly within any strictly palaeontological sub-discipline. Nevertheless, primarily on the basis of article title, with reference to the abstract and keywords where necessary, each article has been assigned as Museum/Education, Micropalaeontology, Palaeobotany, Palynology, Invertebrate Palaeontology, Vertebrate Palaeontology, Taphonomy, Ichnology, Palaeoecology, Epistemology/Philosophy, and Stratigraphy/Geology.