Priabona

Life-forms

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: Antliophora
Ordo: Diptera
Subordo: Brachycera
Infraordo: Muscomorpha
Sectio: Aschiza
Superfamilia: Syrphoidea

Familia: Pipunculidae
Subfamilia: Pipunculinae
Genus: †Priabona
Species (1): P. florissantius
Name

Priabona Archibald et al., 2014
References

Archibald, S.B.; Kehlmaier, C.; Mathewes, R.W. 2014: Early Eocene big headed flies (Diptera: Pipunculidae) from the Okanagan Highlands, western North America. Canadian entomologist, DOI: 10.4039/tce.2013.79 Reference page.

Priabona is an extinct genus of big-headed flies in the dipteran subfamily Nephrocerinae, within which it is one of only two genera. The genus contains a single described species, Priabona florissantius. Priabona is known from a single Late Eocene fossil from western North America.[1]
History and classification

Priabona is known from a compression-impression fossil preserved in fine shale of the Florissant Formation in Colorado.[1] The formation is composed of successive lake deposits which have preserved a diverse assemblage of insects. The insects and plants suggest a climate similar to modern Southeastern North America, with a number of taxa represented that are now found in the subtropics to tropics and confined to the Old World. When Priabona was described, the Florissant formation was considered to be Miocene in age, based on the flora and fauna preserved. Subsequent research and fossil descriptions permitted a re-examined dating, and by 1985 the formation had been reassigned to an Oligocene age.[2] Further refinement of the formation's age using radiometric dating of sanidine crystals has resulted in an age of 34 million years, which places the formation in the Late Eocene Priabonian stage.[3][4][5]

At the time of description the holotype specimen, number 3976 was deposited in the Museum of Comparative Zoology paleontology collections at Harvard University. Placement of the group has changed several times, with Nepherocerus Metanephrocerus Priabona and Protonephrocerus being placed in the pipunculid subfamily Nephrocerinae from 1948 until 2014. The placement of the tribe Protonephrocerini, containing Metanephrocerus and Protonephrocerus, was challenged in 2014 by Kehlmaier, Dierick and Skevington who suggested inclusion of the genera made Nephrocerinae paraphyletic. As such they elevated the tribe Protonephrocerini to the subfamily rank as Protonephrocerinae, leaving only Nephrocerus and Priabona in Nephrocerinae.[6] The species was originally placed into the genus Protonephrocerus by Frank M. Carpenter and F.M. Hull with their type description in 1939. The species was moved in 2014, based on a redescription of the type specimen, to the new genus Priabona. The generic epithet "Priabona" is taken from Priabonian, the age of the Florissant Formation.[1]
Description

P. florissantius has a body length of 4.5 millimetres (0.18 in), with the details of the head mostly indistinct. There appears to be a notch between the eyes which runs halfway up the rear-side of the head capsule. The wings of the holotype are 4.6 millimetres (0.18 in) and hyaline overall, with a darkening of the pterostigma. The femurs of P. florissantius are unique in that they have several darkened spines on the undersides and which have setae on the front and upper sides, a feature absent in Nephrocerus.[1]
References

Archibald, SB; Kehlmaier, C; Mathewes, RW (2014). "Early Eocene big headed flies (Diptera: Pipunculidae) from the Okanagan Highlands, western North America". The Canadian Entomologist. 146 (4): 429–443. doi:10.4039/tce.2013.79.
Tindale, N. B. (1985). "A butterfly-moth (Lepidoptera:Castniidae) form the Oligocene shales of Florissant, Colorado" (PDF). Journal of Research on the Lepidoptera. 24 (1): 31–40.
Ksepka, D.T.; Clarke, J.A. (2009). "Affinities of Palaeospiza bella and the Phylogeny and Biogeography of Mousebirds (Coliiformes)". The Auk. The American Ornithologists' Union. 126 (2): 245–259. doi:10.1525/auk.2009.07178. S2CID 85597698.
Lloyd, K.J.; Eberle, J.J. (2008). "A New Talpid from the Late Eocene of North America". Acta Palaeontologica Polonica. Institute of Paleobiology, Polish Academy of Sciences. 53 (3): 539–543. doi:10.4202/app.2008.0311.
Worley-Georg, M.P.; Eberle, J.J. (2006). "Additions to the Chadronian mammalian fauna, Florissant Formation, Florissant Fossil Beds National Monument, Colorado". Journal of Vertebrate Paleontology. The Society of Vertebrate Paleontology. 26 (3): 685–696. doi:10.1671/0272-4634(2006)26[685:ATTCMF]2.0.CO;2.
Kehlmaier, C; Dierick, M; Skevington, JH (2014). "Micro-CT studies of amber inclusions reveal internal genitalic features of big-headed flies, enabling a systematic placement of Metanephrocerus Aczel, 1948 (Insecta: Diptera: Pipunculidae)". Arthropod Systematics & Phylogeny. 72 (1): 23–36.