''Cifellilestes'' is a genus of early

mammaliaform Mammaliaformes ("mammalian forms") is a clade that contains the crown group mammals and their closest extinct relatives; the group radiated from earlier probainognathian cynodonts. It is defined as the clade originating from the most recent comm ...

from the

Late Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name ...

Morrison Formation of North America. The type and only species, ''C. ciscoensis'', was named in 2022 by Brian M. Davis and colleagues, and was found in the Cisco Mammal Quarry of

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

. The generic name of the animal is in honor of Richard Cifelli, combined with the Greek word "lestes", which means thief. The specific name refers to Cisco, Utah, a ghost town close in close proximity to the location where 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 sever ...

was found. The genus is known from two specimens, OMNH 80538 & 69352. These specimens represent a right and left skull fragment respectively, both preserving partial palate, snout and postcanine dentition. It belongs to the clade Morganucodonta.

References

Morganucodonts Prehistoric cynodont genera Tithonian genera Late Jurassic synapsids of North America Morrison fauna Fossil taxa described in 2022 Monotypic prehistoric animal genera {{Paleo-therapsid-stub