''Ulteramus'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of parasitic wasp in the sawfly family Pamphiliidae. The genus is solely known from an

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

fossil found in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. At the time of its description the new genus was composed of a single species, ''Ulteramus republicensis''.

History and classification

''Ulteramus republicensis'' is known only from one fossil, the part side of the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, specimen number UWBM 77532, which is housed in the collections of the Burke Museum of Natural History in

Seattle, Washington Seattle ( ) is a port, seaport city on the West Coast of the United States. It is the county seat, seat of King County, Washington, King County, Washington (state), Washington. With a 2020 population of 737,015, it is the largest city in bo ...

. The specimen is preserved as a compression fossil in silty yellow to grayish

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

, which was recovered from outcrops of the Tom Thumb Tuff member of the

Klondike Mountain Formation The Klondike Mountain Formation is an Early Eocene (Ypresian) geological formation located in the northeast central area of Washington state. The formation, named for the type location designated in 1962, Klondike Mountain north of Republic, Wash ...

in 1993 by

Wesley Wehr Wesley Conrad Wehr (April 17, 1929 – April 12, 2004) was an American paleontologist and artist best known for his studies of Cenozoic fossil floras in western North America, the Stonerose Interpretive Center, and as a part of the Northwest ...

. The formation is approximately

Early Eocene In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian i ...

Ypresian In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

in age, being radiometrically dated as . ''Ulteramus'' was first studied by the paleoentomologists S. Bruce Archibald from Simon Fraser University in Burnaby, British Columbia and

Alexandr Rasnitsyn Alexandr Pavlovich Rasnitsyn (Russian: Александр Павлович Расницын) is a Russian entomologist, expert in palaeoentomology, and Honored Scientist of the Russian Federation (2001). His scientific interests are centered on ...

of the A. A. Borissiak Paleontological Institute. Their 2015

type description A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have be ...

of the new genus and species was published in the journal '' Canadian Entomologist''. The genus name ''Ulteramus'' was coined by the researchers as a combination of the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

''ramus'' meaning "branch" and ''ulter'' meaning "on the further side". The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''republicensis'' is a reference to the type locality of the species in

Republic, Washington Republic is a city in Ferry County, Washington, United States. The population was 1,073 at the 2010 census, a 12.5% increase over the 2000 census. It is the county seat of Ferry County. It was the largest mining camp in the Republic Mining Distr ...

. Areas of the ''Ulteramus'' wing venation are similar to members of the pamphiliid subfamilies Pamphiliinae and Cephalciinae. The two subfamilies are distinguished from each other on the condition of the wing apex. Longitudinal corrugation of the wing apex is seen in Pamphiliinae, while Cephalciinae genera have an irregularly coriaceous wing apex. The described fossil of ''Ulteramus'' is missing the majority of the wing apex area, but the small portion that is preserved seems to be smooth. However the placement of the junction between the Subcostal2 and Radius vein distinguishes ''Ulteramus'' from all other pamphiliid genera. Due to the incomplete nature of the fossil, placement of the genus into any of the three described subfamilies or creation of a new subfamily was not possible. ''U. republicensis'' was one of three sawfly species described in Archibald & Rasnitsyn's 2015 paper, the other two being '' Ypresiosirex orthosemos'' and '' Cuspilongus cachecreekensis'', both from the

McAbee fossil beds The McAbee Fossil Beds is a Heritage Site that protects an Eocene Epoch fossil locality east of Cache Creek, British Columbia, Canada, just north of and visible from Provincial Highway 97 / the Trans-Canada Highway ( Highway 1). The McAbee Fos ...

in south central British Columbia.

Description

The single described wing of ''U. republicensis'' is incomplete, missing the very basal and apical sections. Additionally the area of the wing between the Radial and Costal veins is either damaged or folded, obscuring vein details. The wing has an even darkened tone to the membrane with a large

pterostigma The pterostigma (plural: pterostigmata) is a group of specialized cells in the outer insect wing, wings of insects, which are often thickened or coloured, and thus stand out from other cells. It is particularly noticeable in dragonfly, dragonfli ...

hardened by

sclerotisation Sclerotization is a biochemical process that produces the rigid shell of sclerotin that comprises an insect's chitinous exoskeleton. It is prominent in the thicker, armored parts of insects and arachnids, especially in the biting mouthparts and s ...

. The wing as preserved has a length of and a width of approximately . The placement of the join between the Sc2 and R veins nearer to the wing base is not seen in other pamphiliids, resembling that of

Xyelidae The Xyelidae are a comparatively species-poor family of sawflies comprising about 80 Extant taxon, extant species in five genera worldwide and is the only family in the superfamily Xyeloidea. The fossil record of the family is extensive, comprisi ...

genera. The Radius vein segment 4 is longer than seen in other pamphiliids, and the vein segment 1 is present, though it isn't well preserved, obscuring some of the morphological details. The short segment 1 is something not seen in the genera '' Caenolyda'', '' Pseudocephaleia'', and '' Kelidoptera''.

References

{{Taxonbar, from=Q26905849 Ypresian insects Fossils of the United States Fossil taxa described in 2015 Prehistoric insects of North America Klondike Mountain Formation