Related Experiment Video
Updated: Jun 12, 2026
08:08
Chicken Recombinant Limbs Assay to Understand Morphogenesis, Patterning, and Early Steps in Cell Differentiation
Published on: January 12, 2022
Limb bone allometry during postnatal ontogeny in non-avian dinosaurs
Brandon M Kilbourne1, Peter J Makovicky
1Department of Geology, Field Museum of Natural History, Chicago, IL 60605, USA. bmkilbou@uchicago.edu
Journal of Anatomy
|June 19, 2010
Summary
Dinosaur limb bones showed varied growth patterns, with theropod femora becoming more robust and hadrosaur hindlimbs more slender. Intraspecific scaling in dinosaurs does not differ between endotherms and ectotherms.
Area of Science:
- Paleontology
- Comparative Anatomy
- Biomechanics
Background:
- Interspecific scaling in tetrapods is well-documented, but ontogenetic scaling within species, especially in dinosaurs, remains understudied.
- Understanding how bone dimensions change during an individual dinosaur's life is crucial for reconstructing their biology and locomotion.
Purpose of the Study:
- To investigate the ontogenetic allometry (changes in proportions during growth) of limb bones (femur, humerus, tibia) in 23 non-avian dinosaur species.
- To compare scaling patterns across different dinosaur groups (theropods, sauropodomorphs, ornithischians) and with other amniotes.
- To explore the relationship between femoral allometry and adult body mass.
Main Methods:
- Log-transformed bone length was regressed against log-transformed bone circumference for femur, humerus, and tibia using reduced major axis bivariate regression.
- Independent contrasts were used to analyze the relationship between femoral allometry and adult body mass.
- Data were analyzed for 23 non-avian dinosaur species, encompassing various taxonomic groups.
Main Results:
- Femora of large theropod species became more robust during ontogeny, while sauropodomorph and most ornithischian femora showed isometric growth.
- Hadrosaur hindlimb elements became significantly more gracile with ontogeny.
- Scaling constants for femora were higher in theropods than non-theropods; tibial and other hindlimb scaling showed less clear taxonomic divisions.
- A significant negative correlation was found between femoral allometry and adult body mass, but not for other limb elements due to small sample size.
- Intraspecific scaling patterns in dinosaurs and other amniotes did not support differences between endothermic and ectothermic taxa.
Conclusions:
- Dinosaur limb bone ontogenetic allometry varied significantly by taxonomic group and bone element.
- Femoral allometry in dinosaurs is negatively correlated with adult body mass.
- Observed intraspecific scaling patterns do not support the hypothesis of distinct scaling between endothermic and ectothermic amniotes.
More Related Videos
05:25Using Inducible Osteoblastic Lineage-Specific Stat3 Knockout Mice to Study Alveolar Bone Remodeling During Orthodontic Tooth Movement
Published on: July 21, 2023
06:49Analysis of Cell Differentiation, Morphogenesis, and Patterning During Chicken Embryogenesis Using the Soaked-Bead Assay
Published on: January 12, 2022
Related Concept Videos
01:09Changes in the Appendicular Skeleton with Age
The upper and lower limb initially develops as a small bulge called a limb bud, which appears on the lateral side of the early embryo. The upper limb bud appears near the end of the fourth week of development, with the lower limb bud appearing shortly after.
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...
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...
01:07Development of the Limb Synovial Joints
Joints form during embryonic development in conjunction with the formation and growth of the associated bones. The embryonic tissue that gives rise to all bones, cartilage, and connective tissues of the body is called mesenchyme.
The mesenchymal stem cells differentiate into chondrocytes that form the hyaline cartilage, and later the cartilaginous model of the bone. This model further transforms into a bone. This process is known as endochondral ossification.
During development, the limbs...
The mesenchymal stem cells differentiate into chondrocytes that form the hyaline cartilage, and later the cartilaginous model of the bone. This model further transforms into a bone. This process is known as endochondral ossification.
During development, the limbs...
01:10Bones of the Lower Limb: Tibia and Fibula
The tibia is the main weight-bearing bone of the lower leg. It is larger than the fibula with which it is paired. The tibia is also the second longest bone in the body and is located right below the skin. The proximal end of the tibia forms the medial and the lateral condyle, which articulates with the condyles of the femur to form the knee joint. Between the articulating surfaces is the irregular elevated area known as the intercondylar eminence that serves as the inferior attachment point for...
01:16Bones of the Lower Limb: Femur and Patella
The femur is the body's longest and strongest bone spanning the thigh region. Its head articulates with the acetabulum of the hip bone to form the hip joint. A minor indentation on the medial side of the femoral head, called the fovea capitis, serves as the site of attachment for the ligament of the head of the femur. This weak ligament spans the femur and acetabulum and supports the hip joint. The narrowed region below the head is the neck of the femur. The inclination angle between the neck...
01:19Bones of the Upper Limb: Humerus
The upper limb consists of the arm, forearm, wrist, and hand bones. The humerus is the single bone of the upper arm region. Proximally, it has a large, spherical, smooth head that articulates with the glenoid cavity of the scapula to form the glenohumeral or shoulder joint. The margin of the head is the anatomical neck, a residual epiphyseal plate. Laterally it extends to form bony projections called the greater tubercle and the lesser tubercle. Next to the tubercles is the surgical neck, a...
01:55Bone Structure
Within the skeletal system, the structure of a bone, or osseous tissue, can be exemplified in a long bone, like the femur, where there are two types of osseous tissue: cortical and cancellous.