zonule Anat.
(ˈzəʊnjuːl)
Also in L. form zonula (ˈzəʊnjʊlə).
[ad. mod.L. zōnula, dim. of L. zōna zone: see -ule.]
1. A little zone: applied spec. to the ring-shaped fibrous structure which forms the suspensory ligament of the crystalline lens (zonule of Zinn).
| 1831 R. Knox Cloquet's Anat. 555 These membraneous folds, which collectively are called the zonule of Zinn, are vascular. 1854 Kölliker Hum. Histol. 390 The zonula is a thin transparent..membrane, stretching from the ora serrata retinæ as far as the border of the lens. 1873 Power tr. Stricker's Histol. III. 354 The zonula-fibres arise from the substance of the vitreous behind the ora serrata. |
2. Geol. (See quot. 1928.)
| 1928 C. L. & M. A. Fenton in Amer. Naturalist XI. 21 We have discussed the need for some term to designate the rocks bearing a faunule with several stratigraphers. In the course of one conversation Dr. Weller suggested ‘zonule’, and it has been approved by others... We propose the term, therefore, with the following definition: A zonule is the stratum or strata which contain a faunule, its thickness and area being limited by the vertical and horizontal range of that faunule. 1958 Bull. Geol. Soc. Amer. LXIX. 113/1 A zonule is a biostratigraphic unit that is recognizable in a sedimentary basin or similar restricted area of sedimentation. 1976 BMR Jrnl. Austral. Geol. & Geophysics I. 109 The assemblage can be referred to the middle Eocene Proteacidites confragosus Zonule on the basis of the presence of the nominate species. |