Which bone feature might indicate the age of an animal?

Bone color and texture can indeed be indicative of the age of an animal. As animals age, their bones undergo various changes, including alterations in color and texture due to changes in mineral content, density, and surface wear. For example, older bones might appear more worn or have a different luster compared to younger bones. This phenomenon can be attributed to the processes of growth and remodeling that bones experience throughout an animal's life, which can lead to distinguishable characteristics that are reflective of age.

The other options, while they may reflect various aspects of an animal's development or general health, do not provide as clear a direct correlation to age as bone color and texture. The length of the bones is more indicative of the animal's growth stage and can vary widely across species. The absence of cartilage is a factor that might be more relevant to specific health conditions rather than a general indicator of age. Overall weight can vary due to numerous factors such as health, diet, and genetics, and does not serve as a reliable indicator of age alone.