WERE NORTH SLOPE DINOSAURS "WARM-BLOODED" or "COLD-BLOODED"? In
the past, paleontologists assumed that all dinosaurs were cold-
blooded like today's reptiles. But beginning in the 1960s, some
scientists began raising the possibility that some dinosaurs
were warm-blooded. In warm-blooded mammals, cross-sections of
their bones show many channels for the internal passage of
blood. In contrast, cold-blooded reptile bones have far fewer
blood channels. Significantly, bones from some types of
dinosaurs show a combination of both patterns, with lots of
blood channels in the bones of juveniles, and fewer in adults.
Dinosaur bones found on the North Slope and studied thus far
exhibit the juvenile pattern, but the debate about this matter
is far from settled. It may be that dinosaurs had a unique type
of metabolism unlike any living animals today.