Trierarchuncus
| Trierarchuncus Temporal range: Late Cretaceous,  | |
|---|---|
| Scientific classification | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Chordata | 
| Clade: | Dinosauria | 
| Clade: | Saurischia | 
| Clade: | Theropoda | 
| Family: | †Alvarezsauridae | 
| Subfamily: | †Parvicursorinae | 
| Genus: | †Trierarchuncus Fowler et al., 2020 | 
| Species: | †T. prairiensis | 
| Binomial name | |
| †Trierarchuncus prairiensis Fowler et al., 2020 | |
Trierarchuncus (meaning "captain hook," after its single-clawed hands) is a monotypic genus of alvarezsaurid theropod which includes a single species, Trierarchuncus prairiensis, mainly known from fossils found in deposits of the Hell Creek Formation in Montana. It is the youngest known alvarezsaurid and one of the last non-avian dinosaurs, going extinct during the Cretaceous–Paleogene extinction event, which occurred approximately 66 million years ago.