2021 splits and lumps

This list is used to show the various splits, lumps, and discoveries, as well as new families, subfamilies, and genera that may crop up.

2021 new families and subfamilies

 * Sternidae: based on Černý and Natale (2021), Sternidae has been promoted into a family, and contains the following subfamilies:
 * Rhynchopinae: based on Černý and Natale (2021), skimmers are now classed as a subfamily of Sternidae.
 * Gyginae: based on Černý and Natale (2021), white terns are now classed as a subfamily of Sternidae.
 * Sterninae: based on Černý and Natale (2021), true terns are now classed as a subfamily of Sternidae.

2021 new genera
Based on Paton et al. (2003) and Černý and Natale (2021), Burhinus has been split into the following three genera:
 * "Burhinus" is an unnamed genus, containing the Double-striped Thick-knee and Peruvian Thick-knee.
 * Burhinus itself is now reduced to the Bush Stone-Curlew.
 * Oedicnemus now includes all the species formerly in Burhinus.