Praepapilio

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Subphylum: Hexapoda
Classis: Insecta
Cladus: Dicondylia
Subclassis: Pterygota
Cladus: Metapterygota
Infraclassis: Neoptera
Cladus: Eumetabola
Cladus: Endopterygota
Superordo: Panorpida
Cladus: Amphiesmenoptera
Ordo: Lepidoptera
Subordo: Glossata
Cladus: Coelolepida
Cladus: Myoglossata
Cladus: Neolepidoptera
Infraordo: Heteroneura
Cladus: Eulepidoptera
Cladus: Ditrysia
Cladus: Apoditrysia
Cladus: Obtectomera
Superfamilia: Papilionoidea

Familia: Papilionidae
Subfamilia: Papilioninae
Tribus: Papilionini
Genus: †Praepapilio
Species: P. colorado – P. gracilis
Name

Praepapilio Durden & Rose, 1978
References

Durden, C.J., Rose, H., 1978. Butterflies from the middle Eocene: The earliest occurrence of fossil Papilionidae. Prarce-Sellards Ser. Tax. Mem. Mus. 29: 1-25.
Nazari, V., Zakharov, E.V. & Sperling, F.A.H. 2007. Phylogeny, historical biogeography, and taxonomic ranking of Parnassiinae (Lepidoptera, Papilionidae) based on morphology and seven genes. Molecular Phylogenetics and Evolution 42(1): 131–156. DOI: 10.1016/j.ympev.2006.06.022 Reference page.

Praepapilio is an extinct genus of swallowtail butterfly from the middle Eocene deposits of Colorado, United States, comparable to the Lutetian epoch in age. The genus is considered to be the only representative of the fossil subfamily Praepapilioninae.[1][3]

Praepapilio is, so far, the only wholly extinct subtaxon known within the swallowtail family. Two species have been described, each from a single fossil find.

Species
P. colorado

The holotype of P. colorado, the type species of the genus, is from the Middle Eocene-aged Green River Shale, Parachute Creek Member, near Raydome, Colorado. Durden and Rose, in their 1978 paper, compare P. colorado to the extant Baronia brevicornis, and suggest that P. gracilis may be the same species as P. colorado, and that the differences between the two are possibly due to sexual dimorphism.
P. gracilis

As with P. colorado, the holotype of P. gracilis was from the same site in Colorado. It differs from the type species in being smaller and more gracile in form, though anatomical differences may be due to sexual dimorphism.
References
Wikispecies has information related to Praepapilio.

Durden, C.J., and H. Rose. 1978. Butterflies from the middle Eocene: the earliest occurrence of fossil Papilionidae (Lepidoptera). Pearce-Sellards Ser. Tex. Mem. Mus. 29: 1-25.
Rienk de Jong (2007). "Estimating time and space in the evolution of the Lepidoptera" (PDF). Tijdschrift voor Entomologie. 150 (2): 319–346. doi:10.1163/22119434-900000233.
Collins, N. Mark; Morris, Michael G. (1985). Threatened Swallowtail Butterflies of the World: The IUCN Red Data Book. Gland & Cambridge: IUCN. ISBN 978-2-88032-603-6 – via Biodiversity Heritage Library.