Peroneus longus, peroneus brevis and peroneus tertius
To properly build the phylogenetic tree, Julia needs information that can connect any of mentioned mammals (bear and monkey) to reptiles. And that could be only the fact that a duckbilled platypus lays eggs similarly like reptiles. So, the platypus is a mammal and relationship with bear and monkey in that way exist, but laying eggs is not characteristic for other mammals.
One way the muscle cell is different from a plant cell is the plant cell has a pigment called chloroplast which gives it its green color.
