These aren't necessarily related to today's Ophiocordyceps fungus. Fungi that take control of arthropods and cause them to climb to disperse spores have convergently evolved more than once, including Arthrophaga myriapodina, which affects millipedes, and is in a different Division (the level above Class) from Ophiocordyceps.
Convergent evolution is more common than you might think. Trees, for example, have separately evolved at least 100 times.
Fungi likely precedes the Dinos by 100's millions of years
Zombie fungi pulled from amber is the makings of a movie ;)