Desarrollo del Esqueleto de Liolaemus scapularis (Iguania: Tropiduridae)

LOBO, F.; ABDALA, F.; SCROCCHI, G. J.

Bollettino del Museo Regionale di Scienze Naturali

Museo Regionale di Scienze Naturali

Año: 1995 vol. 13 p. 77 - 104

0392-758X

The cranial and poscranial skeleton development of Liolaemus scapularis (Iguania: Tropiduridae) was studied. The observations are based on four embryos and one hatched specimen. Here the fully developed chondrocranium, the cranial and poscranial sequences of ossification were described. In the chondrocranium the taenia marginalis shows intraspecific variation closing or not the epioptica fenestra. The pila antotica is reduced, making both fenestra prootica and metop­ tica fused. Among the most interesting features of the osteocranium development we can remark the earlier ossification of the cranium relative to the poscranium; the first bone that arises it ossification is the pterygoid; the ossification of the whole of the dermal mandibular bones occurs between the first two weeks after the clutch; the presence of 60% of the skull bones at 34A stage was verified; in the same stage nearly the totality of dermal bones are present (14/16); prevomers, nasals and posfrontals begin to ossify at the next stage; supraoccipital, epipterygoid and articular ossify before any other chondral element at 35. Among poscranial events we remark the later apparition of distal carpal I and pisiform (34B); clavícula present at 33 stage; chondral bones of both girdles begin to ossify at 34B stage; diaphysis of humerus and femur begin to ossify at 33 and 34A respectively; hemisternons fused in an unique structure at 34B; etc.