ABSTRACT

Morphometric analysis of the marginal spiral outline of Heterostegina populations belonging to the ocalana-matteuccii lineage reveals that it fully fit with a logarithmic spiral identified by two variables: the initial radius (IRex) and the radius increase (Rinc). Spirals tend to become more looser through time as observable also in well-known Mediterranean lineages. Rinc tends to increase along a phyletic line leading to the definition of a trend of neanic acceleration in Heterostegina, defined as the tendency of the marginal spiral to become looser. Ecophenotypical variations, with high value of Rinc in respect to coeval populations, may occur as for other routinely employed biometric values for nummulitids, but the investigated populations can be well-constrained in a Rinc-X bivariate plot, where X indicates the number of undivided chambers. The spiral outline, going looser, seems to tend become a golden spiral, a spiral defined by value of Rinc of 0.306, leading to a recognition of golden selection in Heterostegininae.

摘要

属于ocalana-matteuccii谱系的Heterostegina种群边缘螺旋轮廓的形态计量分析表明，它完全符合由两个变量确定的对数螺旋：初始半径 ( IRex ) 和半径增加 ( Rinc )。随着时间的推移，螺旋往往会变得更加松散，这在著名的地中海血统中也能观察到。Rinc趋向于沿着系统系线增加，导致Heterostegina中新加速趋势的定义，定义为边缘螺旋变得更松散的趋势。Ecophenotypical变化，具有高价值RINC对于同时代的种群，可能会出现其他常规使用的 nummulitids 生物特征值，但调查的种群可以很好地约束在Rinc-X双变量图中，其中X表示未分隔的房间的数量。螺旋轮廓变得更松散，似乎趋向于变成一个金色螺旋，这个螺旋由Rinc的值为0.306定义，导致对异螈亚科的黄金选择的认可。