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Table 3 Landmarks used in this study

From: Morphological evolution and modularity of the caecilian skull

  Landmark position
1 Nasopremaxilla, palatal surface: medial extreme of tooth row
2 Maxillopalatine, lateral surface: posterior extreme
3 Nasopremaxilla, dorsal surface: anteromedial position
4 Nasopremaxilla, dorsal surface: medial suture with frontal
5 Frontal: most lateral suture position with nasal
6 Parietal: suture with os basale along midline
7 Os basale: dorsal extreme of foramen magnum
8 Vomer: posterior extreme, medial to the choana
9 Os basale: ventral extreme of foramen magnum
10 Os basale, ventral surface: anteromedial extreme on the anteriorly projecting process
11 Quadrate: medial extreme of jaw joint articular surface
12 Quadrate: lateral extreme of jaw joint articular surface
13 Nasopremaxilla: lateral suture with frontal
14 Maxillopalatine, interdental plate: anteromedial extreme of tooth row
15 Maxillopalatine, interdental plate: posterolateral extreme
16 Maxillopalatine, interdental plate: anteromedial extreme
17 Maxillopalatine, maxillary plate: anterior extreme
18 Maxillopalatine, maxillary plate: posterior extreme of tooth row
19 Maxillopalatine, maxillary plate: inflection point where bone splits to surround the choana
20 Nasopremaxilla, palatal surface: lateral extreme of tooth row
21 Nasopremaxilla, palatal surface: posteromedial extreme
22 Vomer: medial extreme of tooth row
23 Vomer: lateral extreme of tooth row
24 Os basale, ventral surface: medial position on the muscle ridge
25 Os basale, ventral surface: lateral position on the muscle ridge
26 Os basale, ventral surface: closest position to vomer
27 Os basale: dorsal extreme of occipital condyle
28 Os basale: ventral extreme of occipital condyle
29 Os basale: posterior extreme of fenestra ovalis
30 Os basale: lateral extreme along suture with parietal
31 Squamosal: anteromedial extreme
32 Squamosal: ventral extreme along suture with maxillopalatine
33 Squamosal: posteromedial extreme
34 Squamosal: posteroventral extreme
35 Frontal: suture with nasal along midline
36 Frontal: suture with parietal along midline
37 Frontal: lateral extreme suture with parietal
38 Parietal: suture with frontal along midline
39 Parietal: anterolateral position of parietal
40 Parietal: posterolateral extreme*
41 Maxillopalatine, lateral surface: anterior extreme of tooth row (dorsal)
42 Maxillopalatine, lateral surface: posterior extreme of tooth row, behind last tooth
43 Nasopremaxilla, dorsal surface: posterolateral extreme above tooth row
44 Nasopremaxilla, dorsal surface: anterior extreme of nares opening
45 Nasopremaxilla, dorsal surface: dorsal extreme of nares opening
46 Nasopremaxilla, dorsal surface: lateral extreme of nares opening
47 Nasopremaxilla, dorsal surface: ventral extreme of nares opening
48 Quadrate, lateral surface: anterolateral extreme
49 Maxillopalatine, interdental plate: anterolateral to the most posterior tooth
50 Os basale: anteromedial suture with parietal
51 Maxillopalatine, maxillary plate: posterior extreme of choanal rim
52 Maxillopalatine, maxillary plate: anterior extreme of choanal rim
53 Quadrate, lateral surface: anteromedial extreme
54 Quadrate, lateral surface: maximum curvature of jaw joint articular surface
55 Stapes, lateral aspect: anterior extreme of the rod, positioned midway dorsoventrally*
56 Stapes: position adjacent to posterior extreme of fenestra ovalis*
57 Stapes: position adjacent to anterior extreme of fenestra ovalis*
58 Stapes: position adjacent to dorsal extreme of fenestra ovalis*
59 Stapes: position adjacent to ventral extreme of fenestra ovalis*
60 Pterygoid process of quadrate (or if absent, pterygoid): posteromedial extreme of ventral surface*
61 Pterygoid process of quadrate (or if absent, pterygoid): posterolateral extreme of ventral surface*
62 Pterygoid process of quadrate (or if absent, pterygoid): anteromedial extreme of ventral surface*
63 Maxillopalatine, lateral surface: posterodorsal suture with squamosal*
64 Maxillopalatine, lateral surface: anterodorsal extreme*
65 Maxillopalatine: if tentacular groove present, suture with nasal and frontal*
66 Maxillopalatine: tentacular groove (if present), anterior extreme*
67 Maxillopalatine: tentacular groove (if present), posterior extreme*
68 Maxillopalatine: tentacular groove (if present), ventral extreme*
69 Mesethmoid (if absent, frontal): anteromedial extreme*
70 Mesethmoid (if absent, frontal): posteromedial extreme*
71 Postfrontal (if absent, squamosal): antero-dorsal extreme*
72 Pterygoid (if present): posteromedial extreme of ventral surface*
73 Pterygoid (if present): posterolateral extreme of ventral surface*
74 Pterygoid (if present): anteromedial extreme of ventral surface*
  1. 74 landmarks were placed onto the right-hand side of the cranium of each specimen. 21 landmarks (*) were removed prior to analyses as they were not homologous across all specimens. These 21 landmarks were used to fix curves around structures such as foramina