Then again, Dorsett was a rookie still earning the trust of the coaching staff. His carries rose as the season progressed and by season's end, I would have considered him to be the team's bell cow.
What are your personal qualifiers for that 'bell cow' title?
In my mind, a "bell cow" is the single biggest focus of the offense. He gets the vast majority of the carries in the offense, and is capable of putting the offense on his back. In addition, when the team is in the lead, the "bell cow" is your clock killer (al a Emmitt Smith and - last season - Demarco Murray). In 1977, Robert Newhouse averaged 12.9 carries per game, and Dorsett averaged 14.7 carries. To his credit, his average number of carries over the last half of the season (7 games) went up to 17.1, but it was still a "committee" approach with him and Newhouse.
As to the clock-killing factor, when that 90's Cowboy team got the ball with a lead and 4 minutes to go in the game, it was game over. Everyone in the stadium - and those watching on TV - knew what was coming. It was Emmitt, off LT, Emmitt off RT, etc. The same thing can be said for Earl Campbell's Oiler teams, or Eric Dickerson's Rams & Colts teams, and even for last year's Cowboys. In 1977, however, it was never a case of "here comes Tony" during similar situations. Landry still spread the ball around.
Finally, the only player capable of carrying that 1977 team on his back was #12. Like I said, Dorsett was definitely the "lead back", and I get where you're coming from. It's really a matter iof semantics and how each of us defines "bell cow".