Young Earth Creationism is a variant of Creationism but more absurd and unfounded. YECs believe that everything was created over a period of six normal-length days, but it happened approximately 4004 BCE. Yes, they believe that everything in the Universe is only six thousand years old, believe it.
Astronomers have proven that the universe is over thirteen Billion years old, possibly fifteen billion years old by using indirect measurement of the age of local globular clusters. They have also concluded this from the cosmic microwave background radiation which is consistent with the universe having expanded from a small area during thirteen billion years.    
Australopithecus, when used in conversation with a young earth creationist, leads to "cognitive dissonance" which is the equivalent of a 6 year old learning there is no Santa Claus. However, due to the psychological abuse of several of the Christian Cults in America, several of these will regurgitate the idea that Australopithecus is really an ape, which it is, but sort of misses the point. Most rational people have learned that what is needed is compassion, for the abuse on these people is so horrible and unimaginable. They've been lied to about reality their whole lives. Poor things.
- "Creation Science 101" by Roy Zimmerman Cool video