Phytomyza tiarellae is an insect, but some observations of it appear in an search filtered for unknowns:
https://www.inaturalist.org/observations/identify?quality_grade=needs_id%2Cresearch&iconic_taxa=unknown&taxon_id=349464&place_id=any
While other observations of the same organism appear only in the search filtered for “Insects”
https://www.inaturalist.org/observations/identify?quality_grade=needs_id%2Cresearch&iconic_taxa=Insecta&taxon_id=349464&place_id=any
In both cases the taxon ID number is the same, and appear in the same spot in the taxon tree.