The first dinosaur fossil and the fossil found on the vega island in 1986 were representative of what geological time period?

The correct answer is the late Cretaceous period. There were many fossils found in the area, not just on Vega island, but they were connected to the cretaceous period and were mostly fossils of hadrosaurs, plesiosaurs, and mosasaurs. The first one was found a couple years earlier.