Data from: The past and future of known biodiversity: rates, patterns, and projections of new species over time

Our understanding of biodiversity patterns comes mostly from described species. Here, we analyze how known biodiversity has increased across living organisms. Past research suggested that the number of new species descriptions per year peaked near 1900 and that only ~2 million species exist. Here we find that rates of species descriptions recently accelerated, with the largest numbers of new species per year all in the past ~20 years (2000–2020). The largest groups grew the most quickly during this period, including animals, arthropods, insects, and beetles. But long-term trends in rates of species descriptions were often unrelated to recent rates and richness. For example, rates for fungi have recently increased whereas rates for animals, arthropods, and insects have not. Extrapolating these rates of species descriptions into the future requires considerable caution. Nevertheless, some intriguing patterns are suggested, such as unexpectedly high projected numbers of plants, fungi, arachnids, crustaceans, ray-finned fishes, and amphibians.