Notoparamys

Notoparamys; Temporal range: Ypresian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Family:	†Paramyidae
Subfamily:	†Paramyinae
Genus:	†Notoparamys; Korth, 1984
Type species
	Notoparamys arctios; Korth, 1984
Other species
	Notoparamys blochi Gunnell et al., 2016; Notoparamys costilloi Wood, 1962;

Notoparamys is an extinct genus of paramyine rodent that lived in North America during the Wasatchian.

Description

Notoparamys possessed a midbrain partially exposed between the cerebellum and cerebrum but lacked visible rostral colliculi.^[1] The incisor enamel of Notoparamys costilloi was pauciserial. The mandibular fourth premolar of N. costilloi had a pattern of Hunter-Schreger bands known as an S-type schmelzmuster. Occlusion in N. costilloi was characterised by mesiolingual movement of the mandibular molars across the maxillary ones in a similar fashion to the closely related Paramys.^[2]

References

^ Bertrand, Ornella C.; Amador-Mughal, Farrah; Lang, Madlen M.; Silcox, Mary T. (29 January 2018). "New Virtual Endocasts of Eocene Ischyromyidae and Their Relevance in Evaluating Neurological Changes Occurring Through Time in Rodentia". Journal of Mammalian Evolution. 26 (3): 345–371. doi:10.1007/s10914-017-9425-6. ISSN 1064-7554. Retrieved 30 September 2025 – via Springer Nature Link.
^ Rose, Kenneth D.; Von Koenigswald, Wighart (1 January 2007). "The Marmot-Sized Paramyid Rodent Notoparamys costilloi from the Early Eocene of Wyoming, with Comments on Dental Variation and Occlusion in Paramyids". Bulletin of Carnegie Museum of Natural History. 39: 111–125. doi:10.2992/0145-9058(2007)39[111:TMPRNC]2.0.CO;2. ISSN 0145-9058. Retrieved 20 September 2025 – via BioOne Digital Library.

[1] Bertrand, Ornella C.; Amador-Mughal, Farrah; Lang, Madlen M.; Silcox, Mary T. (29 January 2018). "New Virtual Endocasts of Eocene Ischyromyidae and Their Relevance in Evaluating Neurological Changes Occurring Through Time in Rodentia". Journal of Mammalian Evolution. 26 (3): 345–371. doi:10.1007/s10914-017-9425-6. ISSN 1064-7554. Retrieved 30 September 2025 – via Springer Nature Link.

[2] Rose, Kenneth D.; Von Koenigswald, Wighart (1 January 2007). "The Marmot-Sized Paramyid Rodent Notoparamys costilloi from the Early Eocene of Wyoming, with Comments on Dental Variation and Occlusion in Paramyids". Bulletin of Carnegie Museum of Natural History. 39: 111–125. doi:10.2992/0145-9058(2007)39[111:TMPRNC]2.0.CO;2. ISSN 0145-9058. Retrieved 20 September 2025 – via BioOne Digital Library.

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