Temperocastor, Korth, 2008

Korth, William W., 2008, Cranial morphology, systematics and succession of beavers from the middle Miocene Valentine Formation of Nebraska, USA, Acta Palaeontologica Polonica 53 (2), pp. 169-182 : 178

Genus Temperocastor nov.

Type species: Eucastor valentinensis Stout, 1999 , by monotypy; see below.

Derivation of the name: From Latin, tempero, blend or mix in due proportion; and castor, beaver.

Diagnosis.—Small castoroidine (smaller than Eucastor tortus ); cheek teeth mesodont and rooted, similar in crown−height to species of Eucastor and Monosaulax . Primitive dental characters as in Monosaulax : lingual striids on premolars minute to absent on unworn specimens; parafossettid generally curved and accessory fossettids commonly present on p4; molars maintain primitive castoroid occlusal pattern, mesofossette (−id) forms before elimination of the parafossette (−id) and metafossette (−id). Derived characters shared with Eucastor : procumbent upper incisors (procumbency>100 °); M3 markedly smaller than anterior molars; high, arched upper diastema; ridge on posterior wall of orbit; more anterior position of ascending ramus on mandible (m2 blocked from lateral view). Stratigraphic and geographic range.—Early–late to late

Barstovian (Miocene) of Nebraska.