Jurassic Park IV Logo - No Feathers

The irony is that the sources Crighton used for his depiction of the raptors (Gregory S. Paul's Predatory Dinosaurs of the World and Robert Bakker's The Dinosaur Heresies) actually illustrate them with feathers (though admittedly without wings, which we now know they had). 

Here are some examples from both books (which, I reiterate, were published before JP and were used as sources by Crighton):

Paul: i.imgur.com/oSkMOON.jpg
Bakker: 4.bp.blogspot.com/-tOVV_O-NGQ8…


Why Crighton omitted this is confusing, considering he clearly advocated for the raptor-bird link.