You are viewing the site in preview mode
Skip to main content
| | | |
d: Eye diameter (μm)
|
a: Om-matidia size (μm)
|
Ommatidia shape
|
Approximation of eye geometry used
|
n: Longest row of ommatidia
|
Opening angle of ommatidia (degree)
|
se: Surface of eye (μm²)
|
so: surface of one ommatidium (μm²)
|
Number of ommatidia
|
|---|
| | |
Formula applied →
|
Measured
| |
Flat
|
\( \frac{d}{a} \)
|
nul, by definition
|
\( \pi \times {\left(\frac{d}{2}\right)}^2 \)
|
Quadrate:
|
a²
|
\( \frac{se}{so} \)
|
|
Age
|
Species ↓
|
Specimen ↓
|
Hemispheric
|
\( \frac{\pi \times d}{2\times a} \)
|
\( \frac{180}{n} \)
|
\( 2\pi \times {\left(\frac{d}{2}\right)}^2 \)
|
Hexagonal:
|
\( \begin{array}{l}3\sqrt{3}\hfill \\ {}2\hfill \end{array}\times {\left(\begin{array}{l}a\hfill \\ {}2\hfill \end{array}\right)}^2 \)
|
|
Late Jurassic
|
Rosenfeldia oppeli
|
SMNS 66004
|
3,400
|
53
|
Hexagonal
|
Flat
|
64
|
0.00
|
9,079,203
|
1,824
|
4,976
|
|
Hemispheric
|
101
|
1.79
|
18,158,406
|
9,953
|
|
Palaeopentacheles roettenbacheri
|
SMNS 67903
|
1,100
|
35
|
Quadratic
|
Flat
|
31
|
0.00
|
950,332
|
1,225
|
776
|
|
Hemispheric
|
49
|
3.65
|
1,900,664
|
1,552
|
|
Palaeopolycheles longipes
|
SMNS 63724
|
4,200
|
50
|
Quadratic
|
Flat
|
84
|
0
|
13,854,424
|
2,500
|
5,542
|
|
Hemispheric
|
132
|
1.36
|
27,708,847
|
11,084
|
|
Knebelia totoroi
|
SMNS 67916
|
7,200
|
67.5
|
Quadratic
|
Flat
|
107
|
0
|
40,715,041
|
4,556
|
8,936
|
|
Hemispheric
|
168
|
1.07
|
81,430,082
|
17,872
|
|
Middle Jurassic
|
Proeryon giganteus
|
FSL 170603
|
9,100
|
90
|
Quadratic
|
Flat
|
101
|
0
|
65,038,822
|
8,100
|
8,029
|
|
Hemispheric
|
159
|
1.13
|
130,077,644
|
16,059
|
|
UJF-ID 11547
|
11,000
|
88
|
Quadratic
|
Flat
|
125
|
0
|
95,033,178
|
7,744
|
12,272
|
|
Hemispheric
|
196
|
0.92
|
190,066,356
|
24,544
|
|
UJF-ID 14020*
|
11,600
|
78.8
|
Quadratic
|
Flat
|
147
|
0
|
105,683,177
|
6,209
|
17,020
|
|
Hemispheric
|
231
|
0.78
|
211,366,354
|
34,040
|
|
UPMC-248
|
NA
|
77
|
Quadratic
|
Flat
|
NA
|
NA
|
NA
|
5,929
|
NA
|
|
Hemispheric
|
NA
|
NA
|
NA
|
NA
|
|
Hellerocaris falloti
|
FSL 710108
|
1,900
|
62
|
Quadratic
|
Flat
|
31
|
0
|
2,835,287
|
3,844
|
738
|
|
Hemispheric
|
48
|
3.74
|
5,670,575
|
1,475
|
|
MNHN.F.A50709*
|
850
|
24.25
|
Quadratic
|
Flat
|
35
|
0
|
567,450
|
588
|
965
|
|
Hemispheric
|
55
|
3.27
|
1,134,900
|
1,930
|
|
Willemoesiocaris ovalis
|
MNHN.F.A29521*
|
7,000
|
68.83
|
Quadratic
|
Flat
|
102
|
0
|
38,484,510
|
4,738
|
8,122
|
|
Hemispheric
|
160
|
1.13
|
76,969,020
|
16,245
|
|
Early Jurassic
|
Gabaleryon sp.
|
SMNS 67631
|
1,850
|
55
|
Quadratic
|
Flat
|
34
|
0
|
2,688,025
|
3,025
|
889
|
|
Hemispheric
|
53
|
3.41
|
5,376,050
|
1,777
|
|
Coleia viallii
|
MSNM.i3368
|
5600
|
82
|
Quadratic
|
Flat
|
68
|
0
|
24,630,086
|
6,724
|
3,663
|
|
Hemispheric
|
107
|
1.68
|
49,260,173
|
7,326
|
|
Coleia barrovensis
|
NHMUK.I6589
|
4100
|
66
|
Quadratic
|
Flat
|
62
|
0
|
13,202,543
|
4,356
|
3,031
|
|
Hemispheric
|
98
|
1.84
|
26,405,086
|
6,062
|
- The size of square ommatidial facets corresponds to the measure of their side length; that of hexagonal ommatidial facets corresponds to the distance between to opposite summits of the hexagon, which is in turn equal to two times the side length. The asterisks after specimens registry numbers indicate that given values are based on multiple ommatidia length measurements, in these cases average values are given. Measured values for these specimens are indicated in Table 2. Distances in μm, surfaces in μm2
