Barbero Sofía, Teta Pablo, Cassini Guillermo Hernán
Laboratorio de Biología Integral de Sistemas Evolutivos, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA - CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Pabellón 2, Ciudad Universitaria, Intendente Güiraldes 2160, C1428EHA Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; División Mastozoología, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Av. Ángel Gallardo 470, C1405 Ciudad Autónoma de Buenos Aires, Argentina.
Zoology (Jena). 2023 Feb;156:126066. doi: 10.1016/j.zool.2022.126066. Epub 2022 Dec 15.
The key role of the skull in food intake and processing implicates its morphology should be to some extent adapted to the functional demands present in different diets, while also showing similarities between those which are closely related. Sigmodontine rodents, with a generalist body plan and broad dietary habits, are an interesting case study to explore these relationships. We used linear morphometrics to assess craniomandibular morphology, and explored its relationship with dietary composition and phylogeny in a sample of sigmodontines from central-eastern Argentina, representative of this subfamily's morphological and ecological diversity. We took 26 measurements performed on 558 specimens belonging to 22 species, and resorted to bibliographic information for proportion of food items in their diets, dietary categories, and phylogeny. Multivariate statistical analyses revealed a strong evolutionary integration between morphological traits of crania and mandibles, and a conspicuous relationship between them and dietary composition in our study group, independent of phylogeny. Species of larger sizes exhibited more robust skulls and a tendency towards folivorous diets, whereas smaller species had more gracile craniomandibular apparatuses and diets richer in seeds and invertebrates. Additionally, we used the observed patterns to made predictions of dietary categories for the three species of this region with unknown diets, completing the map of feeding ecology of one of the most researched group of sigmodontines and enabling future studies to further explore this topic. The present work contributes to understanding the link between morphology, ecology and phylogeny in small mammals.
颅骨在食物摄取和加工过程中的关键作用表明，其形态在一定程度上应适应不同饮食中的功能需求，同时在亲缘关系密切的物种之间也存在相似性。具有通才体型和广泛饮食习惯的稻鼠科啮齿动物是探索这些关系的一个有趣案例。我们使用线性形态测量学来评估颅下颌形态，并在来自阿根廷中东部的一组代表该亚科形态和生态多样性的稻鼠样本中，探索其与饮食组成和系统发育的关系。我们对属于22个物种的558个标本进行了26项测量，并参考文献信息获取它们饮食中食物种类的比例、饮食类别和系统发育情况。多变量统计分析表明，颅骨和下颌骨的形态特征之间存在强烈的进化整合，并且在我们的研究组中，它们与饮食组成之间存在显著关系，与系统发育无关。体型较大的物种表现出更粗壮的颅骨，并有食叶性饮食的倾向，而较小的物种则有更纤细的颅下颌结构，饮食中种子和无脊椎动物的含量更高。此外，我们利用观察到的模式对该地区三种饮食未知的物种的饮食类别进行了预测，完善了对研究最多的稻鼠科群体之一的觅食生态图谱，并使未来的研究能够进一步探索这一主题。本研究有助于理解小型哺乳动物形态、生态和系统发育之间的联系。
