Table 1 Definition of the landmarks and semilandmark curves for the cephalon.
From: A dynamic and collaborative database for morphogeometric information of trilobites
Landmarks | |
|---|---|
Number | Definition |
LM1 | Anteriormost point of the sagittal cephalic length without spine |
LM2 | Anteriormost point of the sagittal glabellar length |
LM3 | Intersection between the sagittal axis and the occipital furrow |
LM4 | Posteriormost point of the sagittal cephalic length |
LM5 | Maximum transversal glabellar width |
LM6 | Intersection between the occipital and axial furrows |
LM7 | Intersection between the posterior margin and the axial furrow |
LM8 | Anteriormost end of the eye |
LM9 | Posteriormost end of the eye |
LM10 | Anterior facial suture at the sagittal line |
LM11 | Intersection between the posterior branch of facial suture and the posterior or lateral border furrow |
LM12 | Intersection between the posterior branch of facial suture and the posterior or lateral margin |
LM13 | Anteriormost point of the sagittal (or ex-sagittal) cephalic length (if spiny, LM13 at the tip of the spine) |
LM14 | Lateralmost external point of the eye |
LM15 | Cephalic width at the level of the posterior margin of the occipital ring (LM4). If that point cannot be located, it is defined as the extreme of the genal angle (see Fig. 3). |
LM16 | Tip of the genal angle or spine |
Semilandmarks (curves) | |
Curve | Starting landmark - ending landmark |
Glabella (C.1) | LM2 - LM7 |
Facial suture (C.2) | LM10 - LM12 |
Anterior margin (C.3) | LM13 - LM15 |
Posterior margin (C.4) | LM4 - LM15 |
