Richard Simmons' death certificate sheds no further light on the mystery surrounding his death ... but does provide some interesting details on his final resting place.
In the document obtained by TMZ ... Richard's manner of death is not listed -- instead, it notes the manner of death is still pending an investigation. This explains why there is still no cause of death to report.
However, it appears the fitness guru -- who is actually referred to as a "Health Motivator" on the cert -- has already been laid to rest a week after his death.