GBIF Get Taxon Children

List the direct child taxa of a GBIF Backbone taxon. Given a taxonKey (e.g. a genus), returns its immediate children one rank down (e.g. the species in that genus), with key, scientificName, rank and taxonomicStatus for each. Use to walk DOWN the taxonomic tree. Get a taxonKey from GBIF_match_name or GBIF_search_species. Example: taxon_key=2435194 (genus Panthera) -> Panthera leo (5219404), Panthera onca (5219426), Panthera tigris, etc. No API key required.