Lusorex, Storch & Qiu, 2004

Storch, Gerhard & Qiu, Zhuding, 2004, First complete heterosoricine shrew: A new genus and species from the Miocene of China, Acta Palaeontologica Polonica 49 (3), pp. 357-363 : 357-358

Genus Lusorex nov.

Figs. 1–6 .

Type species: Lusorex taishanensis sp. nov.

Etymology: After Lu, Chinese abbreviated form of Shandong Province, the provenance of the fossil, and sorex (Latin) for shrew.

Diagnosis.—First and second upper and lower molars resemble those of Wilsonosorex Martin, 1978 . Differs from Wilsonosorex by its undivided mesostyle (well−divided in Wilsonosorex ), crest−like and Y−shaped metaconule (a high pointed cusp in Wilsonosorex ), and weaker paraconule of M1–2 (strong and doubled in Wilsonosorex ); discontinuous ectocingulid below protoconid and hypoconid (below protoconid only in Wilsonosorex ), and very sharp, laterally compressed entoconid of m1–2 (less crest−like in Wilsonosorex ). Small size as in W. bateslandensis . Additional diagnostic features include rather small first upper and lower incisors. Differs from all other heterosoricine genera in having well−developed conules on upper molares and reduced ectocingulids on lowers. Postcranial skeleton essentially soricidlike. Differs from other subfamilies, as far as known, by unfused tibia and fibula.

Figures

Fig. 1. Lusorex taishanensis (holotype), early–middle Miocene of Shanwang, Shandong Province, China (IVPP V 13915). The soft body “shadow” is preserved in black.

Fig. 2. Dentition of Lusorex taishanensis: photo− graph (A) and explanatory drawing of the same (B). Above in each: 1st upper incisor to 5th ante− molar in lingual view; middle: 1st lower incisor to 3rd molar in lingual view; below: 1st lower incisor and 2nd molar in labial view.

Fig. 3. Lusorex taishanensis. A. 4th upper premolar to 3rd molar in occlusal view. B. 3rd to 5th lower antemolar (partially) and 1st to 3rd molar in occlusal view. White line delimits antemolars that are concealed by the upper antemolars.

Fig. 4. X−ray image of dentition and lower jaws of Lusorex taishanensis.

Fig. 5. X−ray image of the forelimb of Lusorex taishanensis.

Fig. 6. X−ray image of the shank and hindfoot of Lusorex taishanensis.