I like the images of Deinonychus flicking its feathers to ward off biting midges and sitting very still so that Enanthiornes can get those ticks in that space behind its head and around its backside that it can't reach. Dinosaurs also may have migrated from shore to upland when the seasons changed and had their babies in the uplands. Note that the shore had mud as well as sand and gravel. The size of the stone in river deposits is related to the speed of the river. Gravel means that the river was fast when the stone was dropped.
Sand means it was slower.
Mud means very slow. River velocity changes with river width. Clay is often deposited in an estuary where the water becomes salty, since the ions in the water cause the clay to come out of suspension. River velocities and river sizes change locally and with seasons. Because of the large amount of NJ that was deposited during and after the Cretaceous I think the Delaware was bigger then than now, but specialists will be able to say more.