Written and printed in Latin in 1580 and is 883 pages long. Almost every page has been annotated in both the outer and inner margins before printing. Approximately 200mm x 130mm x 80mm in size. Made from leather hide, papyrus and string/gut (?) binding.
Handed down through several generations.
The title of your 1580 book is "F. Ioan. Duns Scoti, Ordinis Minorum, Theologorum Omnium Eminentissimi, Atque Academiae Subtilium Antesignani, Quaestiones Quarti Voluminis Scripti Oxoniensis Super Sententias" which translates to "F. Ioan. Duns Scotus, of the Order of Friars Minor, to all theologians of the Most Eminent, and also Academy of Subtilium though the leading reformers, on the View of Oxford Questions the Fourth Volume To be written"
John Duns Scotus was a 13th century philosopher on Catholic Doctrine.
Your 16th century book with tooled leather binding was printed on 'laid paper' (not papryus) in Venice by Apud Haeredes Melchioris Sessae, or the heirs of Melchior Sessa. The estimate is based on prices of matches to this printing.