1st known adult T rex footprints found in US

Scientists have discovered the first known series of adult Tyrannosaurus rex footprints in US' North Dakota. The 23-foot-long trackway, found in the Hell Creek Formation, contains four three-toed footprints (two left and two right) dating back 66.5 million years. Scientists said that while bones provide a lot of information about these creatures, footprints reveal behavioural patterns.