What is it about toy manufacturers that they tend to market trains, cars and dinosaurs at boys? My little girl has always liked trains and cars, and has been bugging me for what seems like forever to get her a dinosaur. She doesn't stray too far from the sexual stereotypes though; she likes Rosie from Thomas and his friends, and cars need to be pink and sparkly. Of course she doesn't want a gnarly dino with sharp teeth and claws like the ones her brother has - it has to be pink with big…