Table 1.
Biological definitions of all landmarks and landmark subset categories
| LM # | Abbreviated biological definition | Landmark subsets | Trouble landmarks |
|---|---|---|---|
|
1 |
The dorsal midline point between the growing forebrain and midbrain lobes. |
Non-Facial |
|
|
2 |
The dorso-rostral midline extent of the growing forebrain. |
Non-Facial |
Trouble |
|
3 |
The midline dorsal most extent of the face. |
Nasal |
|
|
4 |
Midline most rostral extent of the medial nasal processes. |
Nasal |
|
|
5 |
The ventral midline point on the primary palate, in the region that develops into the vermillion of the lip. |
Nasal |
|
|
6 (23) |
The border between the medial nasal process and the forebrain, in line with the center of the body of the medial nasal process. |
Nasal |
|
|
7 (24) |
Most dorsal extent of the rostral portion of the lateral nasal process, marking the original rostrolateral intersection of the lateral nasal process and the forbrain. |
Nasal |
Trouble |
|
8 (25) |
The dorso-caudal most point of the lateral nasal process. |
Non-Facial |
|
|
9 (26) |
The caudal most point of the intersection between the lateral nasal process and the maxillary process, representing the caudal end of the future nasolacrimal duct. |
Nasal |
|
|
10 (27) |
The caudo lateral projection of the dorsal edge of the maxillary process. |
Maxillary/Mandibular |
Trouble |
|
11 (28) |
Point at the nasal aperture representing the intersection of the lateral nasal process and the maxillary process. |
Maxillary/Mandibular |
|
|
12 (29) |
The most rostro-ventral intersection between the medial nasal process and the maxillary process. Between E10.5 and E11.5, it shows the growth of the medial nasal process as a contributor to the labial margin. |
Nasal |
|
|
13 (30) |
The rostro-caudal most extension of the lateral nasal prominence, illustrating the rostral growth of the lateral nasal process between E10.5 and E12.5. |
Nasal |
Trouble |
|
14 (31) |
Point representing the middle of the medial side of the nasal aperture as a lateral extent of the medial nasal process. |
Nasal |
|
|
15 (32) |
The dorsal most point of the nasal aperture representing the rostro-dorsal extreme of the border between the medial and lateral nasal processes. |
Nasal |
|
|
16 (33) |
The corner of the developing mouth, found at the most caudo-lateral point on the rostral border of the maxillary and mandibular processes. |
Maxillary/Mandibular |
|
|
17 (34) |
The lateral extent of the center of the maxillary process as it exists in E10.5 and E11.5. |
Maxillary/Mandibular |
Trouble |
|
18 (35) |
The intersection of the buldge of the trigeminal ganglion and the pontine flexure of the developing brain. |
Non-Facial |
Trouble |
|
20 (37) |
The medial, rostral, dorsal corner of the developing mandibular process. |
Maxillary/Mandibular |
|
|
21 (38) |
The ventral caudal most point on the bulge of the growing forebrain, as noted from the lateral perspective. |
Non-Facial |
Trouble |
| 22 | The most caudal midline point on back of the head, just ventral to the midbrain. | Non-Facial |
Simplified biological definitions for all landmarks as well as landmark subset definitions. Full biological and practical definitions are provided in Additional file 1. Definitions of anatomical directions used here are found in Figure 1. Identifications of these landmarks on specimens are found in Figure 2 and in Additional file 5.