Nalacetus is an extinct genus of mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

 belonging to the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Pakicetidae which were endemic to southern Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

 living during the Lutenian stage of the Middle Eocene (48.6 mya—40.4 mya) and existing for approximately .

It was said to be wolf-sized and one of the earliest forms of the order Cetacea

Cetacea

The order Cetacea includes the marine mammals commonly known as whales, dolphins, and porpoises. Cetus is Latin and is used in biological names to mean "whale"; its original meaning, "large sea animal", was more general. It comes from Ancient Greek , meaning "whale" or "any huge fish or sea...

. The fossil record is exclusive to northern Pakistan. Nalacetus was named by Thewissen and Hussain in 1998. Its type is Nalacetus ratimitus. It was considered monophyletic by Uhen (2010).