Translator Disclaimer
1 July 2021 Mandibular Morphology of Stegolophodon pseudolatidens (Proboscidea, Stegodontidae) from the Lower Miocene of Japan
Katsunori Iizumi, Hisao Ando, Kunihiro Suzuki, Yoshiki Koda
Author Affiliations +
Abstract

We describe two well-preserved mandibles of Stegolophodon pseudolatidens (Mammalia, Proboscidea, Stegodontidae) discovered from the lower Miocene (ca. 16.9–16.6 Ma) in Northeast Japan. The mandible of Sl. pseudolatidens is primitive within the Stegodontidae in having a short symphysis with lower tusks, tetralophodont lower molars, and a mandibular canal with the large dorsoventral diameter in the anterior segment. It is characterized by a perpendicular mandibular ramus (forming an almost right angle between the anterior margin of the mandibular ramus and the dorsal horizontal surface of the corpus), and many scratches in mesial direction on the occlusal surface of m3, implying that Sl. pseudolatidens appears to have acquired a proal jaw movement during mastication. While the mandibular morphology of Sl. pseudolatidens is comparable to that of other species of the genus that of Stegolophodon cf. stegodontoides from the upper Miocene of Myanmar differs from that of these species in having a shorter symphysis, which is a derived condition.

© by the Palaeontological Society of Japan
Katsunori Iizumi, Hisao Ando, Kunihiro Suzuki, and Yoshiki Koda "Mandibular Morphology of Stegolophodon pseudolatidens (Proboscidea, Stegodontidae) from the Lower Miocene of Japan," Paleontological Research 25(3), 279-297, (1 July 2021). https://doi.org/10.2517/2020PR025
Received: 16 February 2019; Accepted: 20 June 2020; Published: 1 July 2021
JOURNAL ARTICLE
19 PAGES


Share
SHARE
KEYWORDS
Early Miocene
mandible
Natori Group
Shirado Group
Stegodontidae
Stegolophodon
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top