"This is precisely why excavation was necessary," said USF professor Erin Kimmerle, head of the research project. "The only way to truly establish the facts about the deaths and burials at the school is to follow scientific processes."
The school, infamous for accounts of brutality told by former inmates, was closed by the state in 2011.
The University of South Florida was commissioned to look into deaths at the school in the Panhandle city of Marianna, after the Florida Department of Law Enforcement announced the presence of 31 official grave sites in 2010.
Excavation began last September with bones, teeth and several artifacts from grave sites sent to the University of North Texas Science Center for DNA testing.
Members of 11 families who lost boys at Dozier have been located by the Hillsborough County Sheriff's Office for DNA sampling and researchers hope to find 42 more families for possible matching.
State investigators initially located 31 suspected graves in the woods across a busy highway from the shuttered reform school. Kimmerle's more detailed probes raised the number to 50 or 51 last year, and USF announced on Tuesday the searchers had found remains of 55 bodies.
"Locating 55 burials is a significant finding, which opens up a whole new set of questions for our team," said Kimmerle.
"All of the analyses needed to answer these important questions are yet to be done, but it is our intention to answer as many of these questions as possible."
Research will continue in areas adjacent to the graveyard, dubbed "boot hill" by school officials and inmates a century ago.
Greg Ridgeway, acting director of the National Institute of Justice, praised Kimmerle's work. He said the discoveries made by the USF team "will not only bring resolution to these cases but will add to our knowledge about investigations of missing and unidentified persons in jurisdictions throughout the country."
(Editing by David Adams and Eric Walsh)