Heliscomyidae

Taxobox
name = Heliscomyidae
fossil_range = Middle Eocene to Early Miocene
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = Rodentia
subordo = Castorimorpha
superfamilia = Geomyoidea
familia = †Heliscomyidae
familia_authority = Korth, Wahlert, and Emry, 1991
subdivision_ranks = Genera
subdivision = †"Apletotomeus"
†"Heliscomys"
†"Passaliscomys"
†"Tylionomys"

Heliscomyidae is a family of extinct rodents from the mid-Tertiary of North America related to pocket gophers (family Geomyidae) and kangaroo rats and their relatives (family Heteromyidae). The family contains four genera, †"Apletotomeus", †"Heliscomys", †"Passaliscomys", and †"Tylionomys" (Korth et al., 1991; Korth and Eaton, 2004; Korth and Branciforte, 2007). McKenna and Bell (1997) placed the first two genera in synonymy, with "Heliscomys" the senior synonym.

Characteristics

Heliscomyids are distinguished from other geomyoid rodents by several characteristics of the skull including fusion of three cranial foramina, elongation of the incisive foramina, and an unusual position of the mental foramen (Korth et al., 1991).

Taxonomy

Heliscomyidae is a member of the clade Geomyoidea, a group of rodents that also includes the families †Eomyidae, †Florentiamyidae, Heteromyidae, and Geomyidae. The following cladogram showing interrelationships among geomyoid families follows Korth et al. (1991):

Clade | style=font-size:100%;line-height:100%
label1=Geomyoidea
1=Clade
1=†Eomyidae
2=Clade
1=†Heliscomyidae
2=Clade
1=†Florentiamyidae
2=Clade
1=Geomyidae (pocket gophers)
2=Heteromyidae (kangaroo rats and mice, pocket mice)

References

*Korth, W.W. and C. Branciforte, 2007. Geomyoid rodents (Mammalia) from the Ridgeview Local Fauna, early-early Arikareean (late Oligocene) of western Nebraska. "Annals of Carnegie Museum" 76(3):177-201.
*Korth, W.W. and J.G. Eaton, 2004. Rodents and a marsupial (Mammalia) from the Duchesnean (Eocene) Turtle Basin Local Fauna, Sevier Plateau, Utah. "Bulletin of Carnegie Museum of Natural History" 36(1):109-119.
*Korth, W.W., J.H. Wahlert, and R.J. Emry, 1991. A new species of "Heliscomys" and recognition of the family Heliscomyidae (Geomyoidea: Rodentia) "Journal of Vertebrate Paleontology" 11(2):247-256.
*McKenna, Malcolm C., and Bell, Susan K. 1997. "Classification of Mammals Above the Species Level." Columbia University Press, New York, 631 pp. ISBN 0-231-11013-8