袋鼠厚釉质的偶然演化：抵抗饮食磨损的适应性策略

Aidan M. C. Couzens1*, Benedict King2, Gavin J. Prideaux1 The late Cenozoic period saw widespread diversification of grazing hoofed mammals characterized by high-crowned molar teeth with low, thinly enameled crests. However, Australia’s dominant grazing herbivores, the kangaroos, have much lower-crowned and higher-relief molars that are more akin to some “archaic” placental herbivores. Using x-ray microcomputed tomography scanning, we show that as kangaroos shifted to higher-abrasion grazing diets, their ancestrally vertical, interlocking mode of occlusion favored the acquisition of thick enamel as a durability adaptation. Extant grass-feeding kangaroos have relatively much thicker molar enamel than browsing taxa, especially across the cutting lophs. …