What does the fossil record of Basilosaurid whales tell us about whale evolution? Solution Early whales,like Basilosaurus have tailfins.Such skeletal changes that accommodate an aquatic lifestyle are especially pronounced in basilosaurids.Their elbow joints were able to lock,allowing the forelimb to serve as a better control surface and resist the oncoming flow of water as the animal propelled itself forward.The hindlimbs of these animals were almost nonexistent.They were so tiny but well-formed hind legs of basilosaurids were probably used as claspers when mating.The pelvic bones associated with these hind limbs were not connected to the vertebral column as they were in protocetids.They were fully recognizable whales which lived entirely in the ocean.This is supported by their fossils usually found in deposits indicative of fully marine environments.The fossilised stomach contents in one basilosaurid indicates that it ate fish.From the ear bones to the ankle bones,whales belong with the hippos and other artiodactyls.Basilosaurid are the intermediates between the Ambulocetus and the modern whales..

1. What does the fossil record of Basilosaurid whales tell us about whale evolution?
Solution
Early whales,like Basilosaurus have tailfins.Such skeletal changes that accommodate an aquatic
lifestyle are especially pronounced in basilosaurids.Their elbow joints were able to lock,allowing
the forelimb to serve as a better control surface and resist the oncoming flow of water as the
animal propelled itself forward.The hindlimbs of these animals were almost nonexistent.They
were so tiny but well-formed hind legs of basilosaurids were probably used as claspers when
mating.The pelvic bones associated with these hind limbs were not connected to the vertebral
column as they were in protocetids.They were fully recognizable whales which lived entirely in
the ocean.This is supported by their fossils usually found in deposits indicative of fully marine
environments.The fossilised stomach contents in one basilosaurid indicates that it ate fish.From
the ear bones to the ankle bones,whales belong with the hippos and other
artiodactyls.Basilosaurid are the intermediates between the Ambulocetus and the modern whales.