Genus: Nigchengodon ZHANG, ZHOU & LUO, 2024
Etymology: In reference to the Ningcheng Basin of Inner Mongolia where the type locality of Xidayingzi is located adn and Greek, odon, "tooth."
= Genus: Nova LI, WANG, HU & ZHOU, 1995

Species: foxi ZHANG, ZHOU & LUO, 2024
Etymology: In honor of the late Professor Richard Carr Fox (1933-2022) for his great contribution to the knowledge of fossil mammals.

Holotype: PMOL-AM00036

Locality: Duanjiagou, Xidayingzi Village, Bisiyingzi Township, 41°24'45.78"N, 119°7'10.31"E, Ningcheng County, Inner Mongolia, China.

Horizon: Lujiatung Unit, Yixian Formation, Jehol Group.

Biostratigraphy:

Age: Barremian-Aptian Stage, Early Gallic Subepoch, Middle Early Cretaceous Epoch, Early Cretaceous.

Material: A partial right dentary, preserved with ultimate premolar and 5 molars plus tooth loci of other lower premolars, canine and incisors, as represented by tooth alveoli.