|Pakicetus Illustration by Carl Buell|
Class : Mammalia
Order : Cetacea
Family : Pakicetidae
Genus : Pakicetus
Length : 3ft (.9m)
Weight : 50lbs (23kg)
Status : Extinct since the Early Eocene (40 million years ago)
Take a look at that picture. That little guy is a possible ancestor to dozens of modern mammals. If you had to guess which, would you say dog? Cat? Weasel? Well those would all be wrong! Pakicetus (if you couldn't guess from the taxonomic cheat sheet up there) is an ancient Whale.
Pakicetus gets its name from its location and type. Paki for Pakistan, Cetus for whale. It is the earliest known, well-preserved, prehistoric whale. Pakicetus was a terrestrial, but potentially semi-aquatic animal, since its ears were not yet developed to hear well underwater. Its actual habitat is still debated because it had eye sockets and limbs that might suggest more aquatic activity than initially thought. Other early cetaceans, also found in Central and South Asia, have similar characteristics and are known from more complete skeletons.
Eventually Pakicetus and other early Cetaceans would take to the water more and more, and evolution would do its part to turn arms into fins and tails into flukes. By the end of the Eocene (about 35-30 million years ago) we had fully aquatic whales swimming in the prehistoric seas. Isn't it awesome how life moved out of the oceans, and then creatures like whales eventually went back again? And now animals whose ancestors were dog-like land mammals have become the largest animals to ever live? So cool.