"He suffered a heart attack and passed away at his residence this morning," Dinamalar Editor K Ramasubbu said.
Known as ''RK'', he became the Dinamalar editor in 1977 after joining the daily in 1956, founded by his father T V Ramasubbier. A post-graduate in geology from the Presidency College here, he introduced the now well known ''Periyar'' script which has lesser number of Tamil characters in the newspaper''s Tiruchirappalli edition in 1977.
Later, the Tamil Nadu government came forward to introduce the script in text books and it is widely followed today. He studied in detail the various inscriptions in ''Vattezhuthu'' script in different parts of Tamil Nadu and Kerala and published three books in Tamil on the data collected by him.
"Vattezhuthu is a ''circular'' script that evolved out of the Tamil Brahmi script around fifth-sixth century AD. RK did outstanding research in not only deciphering the script, but also studied the paleographical evolution of the Vattezhut script," noted archaeologist S Ramachandran told PTI.
Krishnamurthy's contribution in discovering several Chera, Roman, and Greek coins had a major role in conclusively establishing that the present day Karur was indeed the Vanji of olden times, he said, condoling his death.
During a time when Tamil Nadu historians did not even have an understanding of Tamil coninage during the Sangam period, it was RK who attracted their attention to the state's numismatic study through his pioneering work, he said.
"He was instrumental in bringing out the famous Karur ring by organising numismatic seminars," Ramachandran said. His stellar work brought to light coins belonging to the Sangam age, be it one on the Pandian king ''Peruvaluthi,'' the Chera silver coins (Maakkothai) or the ''Malaiyaman'' coins.
To help people outside Tamil Nadu to understand the significance, he published a book ''Sangam age Tamil coins'' in English. His participation in various conferences, at regional, national and international level and publication of papers in scholarly journals brought him recognition from scholars and academic bodies.
In recognition of his service and contribution to journalism, Tamil script reform, epigraphy and numismatics, the Madurai Kamaraj University conferred him the honorary degree of Doctor of Science in 2004. He was also a recipient of the ''Tholkappiar Award'' for his work on Tamil script and numismatics in 2015.
The Royal Numismatic Society in London honoured him by electing him as a Fellow and he was president TN Numismatic Society of India since its inception in 1986.