Paleo-art is something close to my own heart, and I think your off to a good start.
Your on the right path and taking the time to do your research is a key part in recreating these fascinating creatures. I do like the way you used your artistic license to go with the partial feathered T-rex.
New research is constantly changing our interpretation in the feather v featherless debate so I think you were correct to go with your choice. Although just for an update, I think the latest research put the T-Rex back to featherless as bio-mechanical tests have revealed that feathers do not offer any advantage for large animals,eg Elephants or Rhino, so natural selection would have favored for thick skin in bio thermal control.
Your going in the right direction trying to tell a story here, but there is some areas you could work on improving.
First is the values, and how the image reads overall. I could talk at length about this, but you will just have to go and spend the time to study and understand this. Basically, everything is getting lost in one another.
In fact the first dinosaur looks like it coming out of the one behind it. There are a few visual tangent issues here also and your value separation is only reinforcing this. Its actually very confusing to read.
Speaking of visual tangents, its very odd to have the background Edmontosaurus out of frame with some of the head area. I don't know if this is a result of your upload or the actual drawing.
Shadows are not matching up to light direction and there are shadows missing where there should be some.
Right now these are fundamental issues. That is to say your understanding of the basics. Spend time to study light and shadow, values, composition, etc.
The dinosaurs look a little stiff, so work on learning gesture and how to translate this. Also remember that they were living breathing animals, so don't forget to try add more in the way of muscles and definition to these areas, it makes all the difference.
If your really interested in getting better, then study anatomy. Go to the zoo, outside, and draw animals in real life. Pets too! You absolutely have to have an excellent grasp on anatomy. This will help you recreate images from imagination.
Overall, I like where your going, just keep at it. You have to walk before you can run. Keep posting your work too. Hope it helps, and good luck with it.