The sophisticated visual system of a tiny Cambrian crustacean: analysis of a stalked fossil compound eye
The sophisticated visual system of a tiny Cambrian crustacean: analysis of a stalked fossil compound eye
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DOI：
10.1098/rspb.2011.1888
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发表时间：
2012-04-07
影响因子：
4.7
通讯作者：
Waloszek, Dieter
中科院分区：
文献类型：
--
作者：
Schoenemann, Brigitte;Castellani, Christopher;Waloszek, Dieter
来自寒武纪的复眼化石，孤立和三维保存，为了解其主人的生活方式和栖息地提供了显着的见解。这里描述的微小的有柄复眼可能拥有太少的小面来形成一个正确的图像，但它们代表了一个用于检测移动物体的复杂系统。眼睛被保存为几乎固体的，狼牙棒状的磷酸盐块，其中一个标本中的横纹肌的原始位置被保留为深腔。对光轴的分析揭示了四个视觉区域，每个视觉区域具有不同的视觉敏锐度特性。它们分别由向前、横向、向后和向内的透镜进行测量。其中最有趣的是瞳孔向内的区域，在这里，光轴，像那些朝向前方的光轴，会与对侧另一只眼睛的光轴发生干涉。其结果是一个三维的视觉网络，不仅涵盖了前面，但也延伸到横向的任何一方。因此，移动物体可以通过宽的三维空间中的二维坐标（其由朝向移动物体定向的那些小平面的两个轴（左眼的一个和右眼的一个）形成）来感知。这种复眼系统使配备有低敏锐度眼睛的小型节肢动物能够有效地估计可能的食物的速度，大小或距离。眼睛被解释为来自早期甲壳类Henningsmoenicaris scutula的个体，指出在通往现代甲壳类的早期进化谱系中存在高度发达的眼睛。
Fossilized compound eyes from the Cambrian, isolated and three-dimensionally preserved, provide remarkable insights into the lifestyle and habitat of their owners. The tiny stalked compound eyes described here probably possessed too few facets to form a proper image, but they represent a sophisticated system for detecting moving objects. The eyes are preserved as almost solid, mace-shaped blocks of phosphate, in which the original positions of the rhabdoms in one specimen are retained as deep cavities. Analysis of the optical axes reveals four visual areas, each with different properties in acuity of vision. They are surveyed by lenses directed forwards, laterally, backwards and inwards, respectively. The most intriguing of these is the putatively inwardly orientated zone, where the optical axes, like those orientated to the front, interfere with axes of the other eye of the contralateral side. The result is a three-dimensional visual net that covers not only the front, but extends also far laterally to either side. Thus, a moving object could be perceived by a two-dimensional coordinate (which is formed by two axes of those facets, one of the left and one of the right eye, which are orientated towards the moving object) in a wide three-dimensional space. This compound eye system enables small arthropods equipped with an eye of low acuity to estimate velocity, size or distance of possible food items efficiently. The eyes are interpreted as having been derived from individuals of the early crustacean Henningsmoenicaris scutula pointing to the existence of highly efficiently developed eyes in the early evolutionary lineage leading towards the modern Crustacea.