Nasal scutum
| n f ag in l la La' m p | Nasals Frontal shield Anterior chin shield Internasals Loreal Supralabials Sublabials Mental parietals | pf pg pro pso pto r so t v | Präfrontalia Rear chin shields Präoculare Präsuboculare Postocularia rostral Supraoculare Front and rear Temporalia First Anterior |
The nasal shields (Latin: Scutum nasale ) or the nasalia for short are horny scales on the head of a scale lizard (Lepidosauria). Like all dandruff, the nasalia can be important in determining the species .
When looking at the head from the side, the nasalia lie in front of the eye in the direction of the muzzle around the nostril. Depending on the type, the scale can be divided or whole. In the first case, the nostril lies exactly on the border of two (rarely more) scales, which are then both referred to as nasalia. The anterior is called the prenasal , the posterior is the postnasale (Scutum postnasale). If the scale is not divided, the nostril lies within the nasal shield. Above the nasals lie the internalsals (also: intermediate nasal shields ). Are species-dependent before the nasalia toward snout Nasorostralen or equal to the rostral . The upper lip shields ( scutum supralabiale ) can be directly adjacent below . Caudally , i.e. in the direction of the tail, the nasal shield borders on the loreal .
The adder (Vipera berus) has an undivided nasal that borders on a nasorostral.
In Duberria lutrix , the undivided nasal borders directly on the rostral.
Nerodia rhombifer has divided nasals. The prenasal is directly adjacent to the rostral.
In the rhinoceros viper (Bitis nasicornis) , the nasalia are transformed into horns.
In the Borneo short-tailed python (Python breitsteini) the undivided nasal is clearly arranged upwards.
See also
literature
- Bruno Dürigen : Germany's amphibians and reptiles: A description and portrayal. Creutz'sche Verlagbuchhandlung, 1897.