Morganucodon is an example of a plant eater likely similar to our direct-line ancestors around this time. It is not a direct human ancestor but is among the early mammaliaforms, close to the lineage leading to true mammals. It likely had a varied diet, but its inclusion here highlights the transition towards more specialized mammalian diets from the broader reptilian ones.

Evolution: Amphibians > Amniotes > Synapsids > Mammalia
Class: Mammaliaforms or maybe Synapsida 
Time Period: Late Triassic to Early Jurassic
Diet: Likely Herbivore