Fig. 4 in European Journal of Taxonomy: a deeper look into a decade of data

Fig. 4. Age of Reference: The average difference of the publication year of an article with those of the publications included in the bibliographic references. Age of Treatment Citations: The average difference between the year of publication of a taxonomic treatment and the cited treatments. New species generally do not include treatment citations. The biggest difference is when a treatment includes the citation of the original treatments by Linnaeus, 1753 for plants or 1758 for animals.