That is the SRS warning lamp. It will be on if there is a fault detected by the passenger's occupancy sensor, but can be for any part of the air bag system, including crash sensors, seat buckles, and airbags. The most common problems on Range Rover Sports are the seat buckles(pretensioners), and the clockspring, for the drivers air bag. You will need to have it diagnosed to find out what needs to be repaired.
Land Rover Master Tech
Independent Land Rover Specialists
Chevy Chase, MD