Relationships between distribution patterns and body size have been documented in many endothermic taxa. However, the evidence for these trends in ectotherms generally is equivocal, and there have been no studies of effects in crocodylians specifically. Here, we examine the relationship between latitudinal distribution and body mass in 20 extant species of crocodylians, as well as the relationships between seven important reproductive variables. Using phylogenetically independent contrasts to inform generalized linear models, we provide the first evidence of a latitudinal effect on adult female body mass in crocodylians. In addition, we explore the relationships between reproductive variables including egg mass, hatchling mass and clutch size. We report no correlation between egg mass and clutch size, upholding previously reported within-species trends. We also find no evidence of a correlation between measures of latitudinal range and incubation temperature, contrasting with the trends found in turtles.

中文翻译：

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现存鳄鱼属的纬向体重效应及其生殖特征关系的初步证据

在许多吸热类群中已经记录了分布模式与体型之间的关系。但是，这些等温线趋势的证据通常是模棱两可的，并且还没有专门研究对鳄鱼的影响。在这里，我们研究了20种现存鳄类的纬度分布与体重之间的关系，以及七个重要的生殖变量之间的关系。使用系统发生学独立的对比来告知广义线性模型，我们提供了对鳄鱼中成年女性体重产生纬度效应的第一个证据。此外，我们探索了包括蛋质量，孵化质量和离合器大小在内的生殖变量之间的关系。我们报告说鸡蛋质量和离合器大小没有相关性，坚持先前报告的物种内趋势。与海龟的趋势相反，我们也没有发现纬度范围和孵化温度之间存在相关性的证据。