While preparing for his doctorate, he started working in Tucumán (1955–61), at the Lillo Foundation, where he later will become Professor of Paleontology and geology.
Thanks to a fellowship from the British Council, he was able to visit Britain, where he spent time working at the University of Glasgow, the University of Reading, and the Natural History Museum in London, where he interacted and collaborated with Thomas Harris.
In 1961 he became a member of the CONICET and was Professor of Paleobotany at the Museum of Natural Sciences of La Plata.
He was distinguished visiting professor at Ohio State University (US, 1984) and upon his return, he worked at the Argentine Museum of Natural Sciences.
[5][6] Archangelsky also described some of the most diverse fossil flora from the Early Cretaceous of the southern Hemisphere from what is now known as the Baqueró Group.