Dicynodont

The Dicynodontia are an infraorder of extinct animals called therapsids. 
They were herbivorous (plant-eating) animals with two tusks; 'dicynodont' means 'two dog tooth'. 
They were the most successful and diverse of the non-mammalian therapsids, with over 70 genera (types) known.

All of them had the same basic body plan. They were built like small tanks, with sturdy legs at each corner. They were not fast movers, but were obviously strong and lived in groups as many plant-eaters do today.This is suggested by the discovery of a fossil toilet area used by Dinodontosaurus. Morgan, James 2013. Giant prehistoric toilet unearthed. BBC Science & Environment.  Their body shape was similar to certain types of modern mammals such as pigs and rhinoceros. 

Fossils discovered in Poland show that dicynodonts survived at least until about 200 million years ago (the Upper Triassic period.  Six fragments of fossil skull bone discovered in Australia (Queensland) may indicate that dicynodonts survived much longer, until about 150 million years ago (the Cretaceous period) in the region called the southern Gondwana. Thulborn T. & Turner S. 2003. The last dicynodont: an Australian Cretaceous relict. Proceedings of the Royal Society of London B 270, 985-993. 

The dicynodonts were a group of therapsids, but were not ancestors to the mammals. The group which evolved into mammals was the cynodonts.

 References 

category:Therapsids