Families and civilizations are, on the most fundamental level, built on relationships.  The third and fourth (final) seasons of the 1991 television seriesDinosaursdelve deeply into the relationships between the individual members of the Sinclair dinosaur family while simultaneously tackling huge societal issues like sexism, rising medical costs, the negative influence of television and advertising, environmentalism and conservationism, and the modern relevance of faith and ritual to everyday life with fervency and an abundance of slapstick humor.  Parents can't help but relate to the extreme characterization of Baby Sinclair as completely possessed by evil upon entering his "Terrible Twos" and will laugh hysterically at Baby's response to the ineffective "solutions" of Dr. Piaget, the babysitter, and his parents.  Teenage rebellion and the angst of growing up are just as outrageously satirized in episodes like "The Son Also Rises" and "Charlene's Flat World" andDinosaurwriters poke fun at the debate about the effects of television and advertising on young children and society in virtually every episode.  The complex issue of conservationism becomes all too personal to Earl in "If You Were a Tree" when he and a tree inadvertantly switch bodies and environmentalism becomes an intergalactic issue in "We Are Not Alone."  Bonus features include seven never-before-seen-on-television episodes that deal with everything from the rituals of growing up to family bonding and the perils of materialism; optional audio commentary for the "Nature Calls" and "Into the Woods" episodes; a look at the incredibly funny, self-absorbed character of Baby with writer Kirk Thatcher, executive producer Brian Henson, and actor/puppeteer Kevin Clash; and a discussion about some of the causes behind theDinosaursseries and how the program's format made it possible to address such far-reaching issues.  BecauseDinosaursfunctions on dual levels, appealing both to children with its silly puppet antics and adults with its pointed social commentary, some parental guidance may be in order for children under 9 years.--Tami Horiuchi