Florida Today reports that hospital officials called police after the woman arrived for treatment Wednesday.
Palm Bay police spokeswoman Yvonne Martinez says 35-year-old Ricardo Marquis Davis confessed to biting off the thumb and spitting it onto the floorboard.
He told police they had gotten into an argument and she had pushed his head while they were driving.
Martinez says doctors were not able to reattach the woman’s thumb. She says police victim advocates are working to help her.
Davis is being held in the Brevard County Jail on aggravated battery charges.