Marge discovers that another character has "diamonds on the soles of her shoes". This is also the title of a song written by Paul Simon and included on the 1986 album "Graceland".
Dr. Bushwell is based on Jane Goodall, who also lived among chimpanzees. Of course, Dr. Goodall was NOT secretly running a diamond mine!
The title of episode is a spoof of the song Surfin' Safari".
CostMo Foods is a parody of Costco.
When the enraged hippo rears up, Homer exclaims "A hungry hungry hippo!", a reference to the popular board game Hungry Hungry Hippos. Incidentally, one of the four hippos in the game is called Homer Hippo.