Officials are still not sure what killed Teena Marie -- this according to the singer's death certificate ... obtained by TMZ.

The coroner who signed the death certificate notes 54-year-old Teena died at 3:09 pm on December 26 -- but in the cause of death section, she checked the box, "Pending investigation."

As we previously reported, officials believe Teena may have died as a result of a massive seizure.

Join me on 96.5 KVKI Saturday nights for Teena and more artists you love from the 80's for the Saturday Night 80's Show! Be there or be square!! 

-Ally

Curtesy of  TMZ.com

http://www.tmz.com/person/teena-marie/