Quinetia

Q. frigidaria holotype.

*Quinetia* is an extinct genus of bats that lived in North Dakota and Belgium during the Early Oligocene.

## History

*Q. misonnei* was reported from the Early Oligocene of Belgium by Horácek (2001), with *Q. frigidaria* named by Czaplewski, Person, Boyd and Emry (2019) from the Early Eocene of the Brule Formation, North Dakota. In 2022, Boyd announced an upper jaw with P4-M2 from the Oligocene of North Dakota, discovered by Trissa Ford, with small differences that may represent a third unnamed species. *Q. frigidaria* derives from "of cooling", after the cooling event at the same time, which could have plausibly affected bat taxa.

## Description

NDGS 1691 is the holotype and only known specimen of *Q. frigidaria*, a right maxilla and anterior root of zygomatic arch, orbital floor and part of the infraorbital canal with P4-M3. It is diagnosed by being medium-sized and larger than *Q. misonnei*, with a short infraorbital canal, upper molars without hypoconal shelves and hypocones, mesostyles from the labial edge of the molars, relatively deep and narrow anterior-and-posterior ectoflexids, low and distinct paraconules and metaconules and distinct conular crests. It is distinct from *Stehlinia* based on a much shirter hypoconal shelves on the M1-M2 and less prominent metaconule on M1-M2. From *Chadronycteris*, it is distinct from a shorter infraorbital canal, a less pronounced anterior shelf on the P4 and with M1-M2 with postprotocrista that do not persist to the metacingulum, thinner lingual cingulum and distinct paraconule and paraconular crests.

## Paleoecology

The Brule Formation of Fitterer Ranch, Stark Country, North Dakota. The lower sector (units 4-6A) yield a biota of the Early Oligocene that were interpretated by Hoganson and Lammers (1985, 1992) as being savanna-adapted with taxa that may represent a riparian gallery woodland with open savanna and shallow ponds. Vertebrate fauna from here are primarily reported in faunal lists without further discussion. Bat specimens are foun in the lower Brule as well, but no detailed descriptions or discussion were published until the publication of *Q. frigidaria* in 2019. This area is considered to have been Orellan or Whitneyan in age, with fauna representative of this transition in the lower levels and characteristic Whitneyan fauna in the upper layer. *Q. frigidaria* is part of a Paleogene bat radiation near the low point of the Eocene-Early Oligocene global temperature decline, increased seasonal aridity and loss of tropical midlatitude North American flora.

Rodents include *Agnotocastor praetereadens*, *Heliscomys medius*, *Eumys brachyodus* and *Hesperopetes jamesi*. Artiodactyls include *Miniochoerus bullatus*, and (from the "bonebreccia" bed) rich remains of freshwater gastropods, fishes, anurans, lizards, snakes, small birds and many small mammals with *Leptomeryx*, *Mesohippus* and others all found with no articulation or association. Q. frigidaria is specifically from the "bonebreccia", which occurs at the base of Unit 6A in the local channel, with some believing it cuts down Unit 5E. Bats from this site are known from the Whitneyan fauna, but further time specification is yet unknown. This extends the geographic and biostratigraphic range of early vespertilionids and fills a previously absent record in bat evolution. This sequence has thick beds of coarse channel sandstone that indicates active streams that flowed through this area. Thus, some of this fauna represent a riperian habitat. Other unidentified bats are reported from the same fauna.

## References

* https://repository.si.edu/bitstream/handle/10088/104588/2019\_Czaplewski\_376.pdf?sequence=1&isAllowed=y
* https://www.mindat.org/taxon-P378929.html
* https://twitter.com/boydpaleo/status/1507496192040738827