Patterns of skull shape variation in Meriones persicus (Rodentia: Muridae) in relation to geoclimatical conditions

Document Type : Research articles



This study investigates skull variation in Persian jird, Meriones persicus (Blanford, 1875) in
relation to the geoclimatical conditions across its distribution range. The pattern of
correlations between geoclimatical variables and geometric shape descriptors for 221
ventral crania was studied by landmark-based geometric morphometric techniques. The
covariation between shape and geoclimatical variables was explored using the Two-Block
Partial Least-Squares (2B-PLS) method. The studied geoclimatical variables are: altitude,
temperature (mean annual, monthly maximum and monthly minimum), annual rainfall
and seasonal variation in rainfall represented by the Shannon rainfall diversity index. The
phenotypes of this species reflect a particular pattern of correlated shape variation to the
geoclimatical variation. The Persian jirds from the Southern populations living in lower,
warmer and drier localities are characterized by bulla hypertrophy, less convex zygomatic
arch, narrower zygomatic plate, longer incisive foramen and slightly a shorter nasal. The
studied populations which belong to different subspecies differ from each other through
a smooth variation in cranial characters.