A macroevolutionary pathway to megaherbivory

• 成果类型: Article
• 署名作者: Sanisidro, Oscar; Mihlbachler, Matthew C.; Cantalapiedra, Juan L.
• 署名单位: Universidad de Alcala; New York Institute Technology; American Museum of Natural History (AMNH)
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-9053
• DOI: 10.1126/science.ade1833
• 发表日期: 2023-05-11
• 页码: 616-618
• 关键词: body-size; copes rule; EVOLUTION; extinction; mammals

摘要

Several scenarios have been proposed to explain rapid net size increases in some early Cenozoic mammalian lineages: sustained and gradual directional change, successive occupation of adaptive zones associated with progressively larger body sizes, and nondirectional evolution associated with branching events in combination with higher diversification potential of the larger lineages. We test these hypotheses in brontotheres, which are among the first radiations of mammals that consistently evolved multitonne sizes. Body-mass evolution in brontotheres mainly occurred during speciation and had no preferential direction. Long-term directional change stemmed from the higher survival of larger lineages in less-saturated herbivore guilds. Our study emphasizes the role of differential species proliferation in explaining the long-term phenotypic trends observed in the fossil record, which are more than an accumulation of steady microevolutionary changes.