Smith Stephanie M, Angielczyk Kenneth D, Schmitz Lars, Wang Steve C
Department of Biology and Burke Museum of Natural History and Culture, University of Washington, Seattle, Washington.
Integrative Research Center, Field Museum of Natural History, Chicago, Illinois.
Anat Rec (Hoboken). 2018 Oct;301(10):1774-1787. doi: 10.1002/ar.23900. Epub 2018 Oct 17.
Diel activity pattern (DAP) is a key aspect of an animal's ecology, but it is difficult to infer when behavior cannot be directly observed, as in the fossil record. Various anatomical correlates have therefore been used to attempt to classify DAP. Eyeball dimensions are good predictors of DAP because they relate directly to light sensitivity of the eye. Osteological characters, such as scleral ring dimensions, are also reliable proxies, but bony orbit dimensions alone have proven less reliable because soft tissues other than the eyeball can affect orbit size and shape. However, it would be useful if bony orbit dimensions could be used to determine DAP, particularly for mammals, which have no scleral ring, and nonmammalian synapsids, which infrequently preserve scleral rings. We investigated the possibility of predicting DAP in sciurids (Mammalia: Rodentia: Sciuridae) using orbit measurements and other cranial dimensions, and a variety of quantitative methods, including phylogenetic flexible discriminant analysis, classification trees, and logistic regression. The latter two methods do not require a priori assignment of DAP and therefore reflect the situation in a fossil data set. We find that although there are some interfering phylogenetic factors, nocturnal and non-nocturnal sciurids can be differentiated from one another with over 80% accuracy using all methods investigated here; attempts to differentiate crepuscular animals from nocturnal and diurnal species proved much less successful. Our results indicate that these analyses offer several viable options for predicting DAP in the fossil record, but such analyses should be conducted in a phylogenetic context whenever possible. Anat Rec, 301:1774-1787, 2018. © 2018 Wiley Periodicals, Inc.
昼夜活动模式（DAP）是动物生态学的一个关键方面，但当行为无法直接观察到时，就像在化石记录中那样，很难进行推断。因此，人们使用了各种解剖学关联特征来尝试对昼夜活动模式进行分类。眼球尺寸是昼夜活动模式的良好预测指标，因为它们与眼睛的光敏感度直接相关。骨骼特征，如巩膜环尺寸，也是可靠的替代指标，但仅眼眶骨骼尺寸已被证明不太可靠，因为除眼球外的软组织会影响眼眶的大小和形状。然而，如果能用眼眶骨骼尺寸来确定昼夜活动模式，那将是很有用的，特别是对于没有巩膜环的哺乳动物，以及很少保存巩膜环的非哺乳类合弓动物。我们研究了使用眼眶测量数据和其他颅骨尺寸，以及包括系统发育灵活判别分析、分类树和逻辑回归在内的各种定量方法来预测松鼠科动物（哺乳纲：啮齿目：松鼠科）昼夜活动模式的可能性。后两种方法不需要预先确定昼夜活动模式，因此反映了化石数据集中的情况。我们发现，尽管存在一些干扰系统发育的因素，但使用这里研究的所有方法，夜间活动和非夜间活动的松鼠科动物能够以超过80%的准确率相互区分；将晨昏性动物与夜间和昼间物种区分开来的尝试则远没有那么成功。我们的结果表明，这些分析为预测化石记录中的昼夜活动模式提供了几种可行的选择，但只要有可能，此类分析应在系统发育背景下进行。《解剖学记录》，301:1774 - 1787，2018年。© 2018威利期刊公司。
