The grisly remains are believed to be part of a Roman cemetery dating back to 410AD.
The latest excavation was carried out over more than a year by Cotswold Archaeology and Oxford Archaeology , working on behalf of a HS2 contractor.Copa senior project manager Richard Brown said:"The excavation is significant in both enabling a clear characterisation of this Roman town but also a study of many of its inhabitants.
"Along with several new Roman settlement sites discovered during the HS2 works it enhances and populates the map of Roman Buckinghamshire."Fleet Marston is one of more than 100 archaeological sites examined by HS2 since 2018 on the route of the first phase of the railway between London and Birmingham.
HS2 Ltd's head of heritage Helen Wass said:"The HS2 archaeology programme has enabled us to learn more about our rich history in Britain. "The large Roman cemetery at Fleet Marston will enable us to gain a detailed insight into the residents of Fleet Marston and the wider Roman Britain landscape. "All human remains uncovered will be treated with dignity, care and respect and our discoveries will be shared with the community."