Relict-lineage
Guides
Horologionini
Horologionini is a relict tribe of carabid beetles (Coleoptera: Carabidae: Trechinae) containing the enigmatic genus Horologion. The tribe was newly recognized in 2024 based on DNA sequence data and morphological analysis. Phylogenetic analysis places Horologionini in the supertribe Trechitae as sister to the Gondwanan tribe Bembidarenini, rejecting previous hypotheses that placed the genus near Anillini, Tachyini, Trechini, Patrobini, or Psydrini. The tribe has no close relatives in the Northern Hemisphere and represents an important component of Appalachian biodiversity.
Necrophilus hydrophiloides
flat brown scavenger beetle
Necrophilus hydrophiloides is a species of primitive carrion beetle in the family Agyrtidae, commonly known as the flat brown scavenger beetle. It belongs to a relict lineage of beetles that represent an early-diverging branch of the staphylinoid beetles. The species is found in western North America, where it inhabits moist forest habitats and is associated with carrion and decaying organic matter.
Spanglerogyrus albiventris
Spanglerogyrus albiventris is a whirligig beetle in the family Gyrinidae, described in 1979 from specimens collected in southern Alabama. It is the sole extant species in its genus and the only living member of the subfamily Spanglerogyrinae, which represents the earliest diverging lineage among extant gyrinids. The subfamily also includes the extinct genus Angarogyrus from the Jurassic and Cretaceous of Asia.