Turner racked up 24 catches for 294 yards and one touchdown across his four years in College Park.
The Big Ten halted play Tuesday, but it left open the possibility of conducting a spring season.
Tagovailoa transferred from Alabama in May.
Jackson is one of four starters from last year's team to opt out.
The group seeks to diversify the collegiate and professional coaching ranks.
Venerable is a three-star defensive back from Maryland.
Bam's older brother, Anthony, is a redshirt freshman defensive lineman for the Terps.
He previously committed to LSU in December.