<< a whirligig beetle species, Heterogyrus milloti, inhabiting forest streams in southeastern Madagascar is the last survivor of a once dominant and widespread Mesozoic group. With a Late Triassic to Early Jurassic origin (226–187 Ma) it is the hitherto oldest dated endemic lineage of animal or plant on Madagascar >>
Grey T. Gustafson, Alexander A. Prokin, et al. Tip-dated phylogeny of whirligig beetles reveals ancient lineage surviving on Madagascar. Scientific Reports 2017; 7 (8619) doi: 10.1038/s41598-017-08403-1
https://www.nature.com/articles/s41598-017-08403-1
<< Even today, the ageless striped whirligig beetle keeps its own company, preferring to skitter atop the surface of out-of-the-way forest streams in southeastern Madagascar—not mixing with latecomers of the subfamily Gyrininae who have become the dominant whirligig beetles on Madagascar and abroad >>
Meet Madagascar's oldest animal lineage, a whirligig beetle with 206-million-year-old origins. Oct 4, 2017
https://m.phys.org/news/2017-10-madagascar-oldest-animal-lineage-whirligig.html