戈壁锯齿象(Serridentinus gobiensis Osborn & Granger, 1932)和同心中新乳齿象(Miomastodon tongxinensis Chen, 1978)再研究：关于粗壮型轭齿象(Zygolophodon)的讨论

王世骐, 张晓晓, 李春晓

Reappraisal of Serridentinus gobiensis Osborn & Granger and Miomastodon tongxinensis Chen: the validity of Miomastodon

WANG Shi-Qi, ZHANG Xiao-Xiao, LI Chun-Xiao

Table 3 Comparison of mandible and dentition among selected species of Zygolophodon, Miomastodon, and Gomphotherium

Taxa Zygolophodon turicensis Miomastodon merriami Miomastodon gobiensis Gomphotherium productum complex Gomphotherium subtapiroideum/tassyi elongation of mandibular symphysis moderately elongated weakly elongated moderately elongated moderately elongated moderately elongated inclination of mandibular symphysis slightly ventrally inclined slightly ventrally inclined slightly ventrally inclined strongly ventrally inclined strongly ventrally inclined posterior mental foramina ? present absent present present cross-section of mandibular tusk laid oval erected oval erected oval laid oval to circular pyriform protrusion of mandibular tusk short short short short long enamel thickness thin thick thick thick thick mesiodistal distance of interlophids wide moderate moderate narrow moderate pretrite central conules absent absent or small small and singular large and serrate small, singular or subdivided posttrite half lophids strongly subdivided moderately subdivided moderately subdivided weakly subdivided or undivided weakly subdivided or undivided posttrite main cuspid and mesoconelet separation clear or unclear separation unclear separation unclear separation clear separation clear alternative position and chevron absent absent present absent absent