"Name one prominent scientist of the last 150 years who now looks like a "stodgy conservative."

Distinguished scientists, such as Harold Jeffreys ( died 1989) and Charles Schuchert (died 1942 - 25 years before the Glomar Challenger), were outspoken critics of continental drift."

Jeffreys was a strong opponent of continental drift. For him, continental drift was "out of the question" because no force even remotely strong enough to move the continents across the Earth's surface was evident.

Starting from August 1968, the Glomar Challenger embarked on a 15 year-long scientific expedition, the Deep Sea Drilling Program, cris-crossing the Mid-Atlantic Ridge between South America and Africa and drilling core samples at specific locations. When the age of the samples was determined by paleontological and isotopic dating studies, this provided conclusive evidence for the seafloor spreading hypothesis, and, consequently, for plate tectonics.

Until the Glomar Challenger, there was no physical mechanism to explain continental drift... or the Ring of Fire or how mountains arise.... so there was lively debate.   That debate is over and plate tectonics accepted by the scientific community.