dissertation co-advisor; dissertation auxiliary/ancillary advisor

Explanation:
My take on it.

https://gap.stanford.edu/handbooks/gap-handbook/chapter-3/su...
3.3.1 Academic Advising: Policy
Last updated on:
Wednesday, April 18, 2018
Summary
Provides that all graduate students are to receive appropriate advising throughout their degree programs.

Rationale
Effective academic advising is a critical component of a successful graduate degree program. At Stanford, all matriculated graduate students are to be advised by a member of the faculty. The nature of academic advising may differ for different programs and at different stages in a degree program.
The department should also ensure that doctoral students are informed in a timely fashion about procedures for selecting a principal dissertation advisor, reading committee members, and orals committee members. Departments should make every effort to assist doctoral students who are not yet admitted to candidacy in finding an appropriate principal dissertation advisor, and dissertation co-advisor if appropriate.

www.njit.edu
New Jersey Institute of Technology
Collaborative Ph.D. Programs
... must be an active researcher and may serve as the candidate's dissertation co-advisor; the main advisor will be an NJIT faculty member

mse.seas.upenn.edu
Doctoral Students
A student may have both a Dissertation Advisor and a Dissertation Co-Advisor...

Michael W. Morris | Columbia University
columbia.academia.edu
CURRICULUM VITAE
Michael W. Morris
2011
GSB, Columbia University 2700 Broadway
NY, NY 10027 NY, NY 10025
(212) 854-2296 (212) 932-2831
Education
1986 B.A. in Cognitive Science and in English Literature, Brown University,
Honors in Cognitive Science
Magna Cum Laude
1993 Ph.D. in Social Psychology, University of Michigan
Dissertation: “Culture and Cause: American and Chinese Understandings of
Physical and Social Causality”
Chair: Richard E. Nisbett

Past Advisees and their Academic Placement

Primary Advisor
Steve Su, INSEAD, Organizational Behavior
Tanya Menon, University of Chicago, Decisions and Organizations
Maia Young, UCLA Organizational Behavior
Emily Amanatullah, UT-Austin, Organizational Behavior
Roy Chua, Harvard Business School, Management
Canny Zou, London Business School, Management
Aurelia Mok, City University of Hong Kong, Management
Shira Mor, ongoing

Auxiliary Advisor

Jennifer Aaker, Stanford, Marketing
Sheena Iyengar, Columbia, Management
Donnel Briley, Sydney, Marketing
Damien Sim, National University of Singapore
Aimee Drolet, UCLA, Marketing
Katherine Phillips (nee Williams), Northwestern, Organizational Behavior