| heterochronic mechanisms of morphological diversification and evolutionary change in the neotropical salamander, bolitoglossa occidentalis (amphibia: plethodontidae). | bolitoglossa occidentalis, a lowland salamander of mexico and guatemala, has a highly derived morphology. the features that are derived with respect to the condition in generalized members of the genus include the following: (1) small body size; (2) short tail; (3) fully webbed hands and feet; (4) reduction and loss of certain phalangeal elements; (5) fusion of carpals and tarsals; (6) absence of prefrontal bones; and (7) reduced skull ossification. the ontogeny of this species was analyzed quan ... | 1981 | 30119585 |