The data is from my own research - the written report is published here, and the complete list of names (with status and species) is online here.

I made the diagram using SankeyMATIC.

Really cool resource you've put together and a great demonstration of how scientific names aren't just exclusive snobbery, and are really necessary when talking about plants and animals, even within one language, let alone multiple. Good job!

Thank you! It's been such satisfying research to work on.

Why a Sankey chart? I'd expect someone accustomed to taxonomic trees to use something less tree-like for this different conceptual separation.

It seemed like the obvious choice to represent the filtering process each name went through - it is conceptually tree-like so naturally the diagram will be! What would you have used?

Pie chart. Because each is a subunit of the whole.