It is possible that your team orally established a partnership (see http://business.ca.gov/StartaBusiness/DefiningaBusiness/Gene... if you're in CA). State law will determine what interest each of the partners has in the event that no written agreement exists that lays this out. You should definitely talk to a friend who is a lawyer, or reach out through LinkedIn to find one you can trust. Good luck, and feel free to find me at gmail if you want to chat further.