One of my more awed touring experiences occurs twice-annually on the Interstates through New York and Pennsylvania. What massive shiftings of earth, water, pressure and fire are written in those sections of rock!
I appreciate very much your very complete response; however, am I not correct in saying that a long chunk of Africa remains stuck within the boundaries of North America to this day?
Perhaps what I should have written was:
...the fossils were among the first animals to live on land in North America which was originally a piece of Africa within the boundaries of North America..."
(If that is indeed true).
No, because the collision with Africa occurred some 150 million or so years *after* the time of the fossilized creatures. However, there ARE pieces of Africa (actually “pro-Africa”) stuck to portions of the east coast. In fact, one dividing line between the two great land masses lies at the approximate location of the Connecticut Valley. On one side, the original North American continent, the other old Africa.
To add, the land that the fossils are embedded in was never part of proto-Africa. The collision with Africa took place further east, and so any portions of ‘Africa’ which stuck following the eventual separation are further east.