Related Experiment Video
Updated: Oct 3, 2026

Skeletal Phenotype Analysis of a Conditional Stat3 Deletion Mouse Model
Published on: July 3, 2020
Postnatal skeletal ontogeny in Callisaurus draconoides and Uta stansburiana (Iguania: Phrynosomatidae)
1Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520, USA. maisano@mail.utexas.edu
Abstract:
The mineralization of the skeleton from hatching to near maximum size in two phrynosomatid lizards, Callisaurus draconoides and Uta stansburiana, is described in detail. Observed patterns in the appearance of epiphyseal secondary centers, ossification centers, apophyseal ossifications, and calcifications, the distribution of sesamoids, and the timing of fusions, are compared and contrasted with observations of other squamates available in the literature. Overall, Callisaurus and Uta exhibit an advanced state of ossification in the hatchling relative to other squamate neonates and share a similar sequence of braincase fusions and appearance of secondary centers. Preliminary observations suggest that patterns of postnatal skeletal development are highly conserved and independent of patterns of prenatal morphogenesis, and thus a potentially rich source of character data for systematic investigations.
Related Concept Videos
Changes in the Appendicular Skeleton with Age
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
Bone Formation by Intramembranous Ossification
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into...
Overview of the Axial Skeleton
The axial skeleton of the adult...
Bone Formation by Endochondral Ossification
Sutures of the Skull
Sutures are immobile joints between adjacent bones of the skull. The narrow gap between the bones is filled with dense, fibrous connective tissue that unites the bones. The long sutures located between the skull bones are not straight but instead follow irregular, tightly twisting paths. These twisting lines tightly...
Introduction to the Skeletal System
Components of the Skeletal System
Bone, or osseous tissue, is a hard connective tissue that forms an internal support structure for the human body. Bones shield vulnerable organs and soft tissue from external forces. For example, the vertebral bones protect and support the spinal cord.
Cartilage, a semi-rigid connective tissue found in regions such as...

