what is the predecessor to the blue whale?

Answer 1

Blue whale is a whlale----

The earliest proto-whale that has been discovered is now Pakicetus, one of a group of creatures labelled the Pakicetids which lived around 52 million years ago. Pakicetus was about the size of a wolf. It looked NOTHING like a WHALE , and more like a cross between a large dog and a rat, having a long, thick tail. Despite this, many features of its skeleton link Pakicetus more CLOSELY to WHALESs than to any other family.

Four-legged, terrestrial ancestors of whales and other cetaceans waded into the sea about 55 million years ago and gradually developed skeletal adaptations for aquatic life, paleontologists hold.