Science & Tech · Science & Environment · 6 hrs ago
Four fossil footprints may show an adult T. rex walking
Colorado high school teacher Kent Hups found four large fossil footprints while volunteering on a dig in southwestern North Dakota in 2025.
Researchers say the 66.5-million-year-old prints were likely made by an adult Tyrannosaurus rex.
They form a trackway, or a series of steps, and are the first known sequence attributed to an adult T. rex.
Before this find, researchers had described only two isolated footprints linked to an adult of the species.
The tracks suggest the dinosaur was walking at about 3.5 to 4.5 miles per hour, based on the distance between its steps.
Fossil bones show what an animal looked like, while footprints can preserve evidence of how it moved at a particular moment.
Four fossil footprints in North Dakota may be the first known trackway made by an adult Tyrannosaurus rex.
The prints are about 66.5 million years old and were likely left by an adult T. rex, researchers say.
Colorado teacher Kent Hups found the first print while volunteering on a fossil dig in July 2025.
The four tracks indicate the animal was walking at an estimated 3.5 to 4.5 miles per hour.
- Who
- The footprints were likely made by an adult Tyrannosaurus rex. Colorado teacher Kent Hups discovered the first print.
- What
- Four fossil footprints form a trackway, a sequence of steps. Researchers say it may be the first recorded trackway of an adult T. rex.
- When
- The tracks date to about 66.5 million years ago. Hups found the first print in July 2025.
- Where
- On federal land near Marmarth in southwestern North Dakota, in the Hell Creek Formation.
- Why
- The size, shape and location of the prints led researchers to attribute them to T. rex.
This story does not have two clearly opposing sides.
My first reaction was total disbelief. I sat and looked at it for a period of time before I was convinced it was a track at all.
Their feet are very different
Bones tell us an enormous amount about these animals, but footprints capture a moment of behavior
Kent Hups noticed a possible footprint while volunteering on a fossil dig in southwestern North Dakota.
The returning team found more prints, bringing the total to four.
- Age of footprints
- About 66.5 million years
- Number of prints
- Four
- Location
- Near Marmarth, southwestern North Dakota
- Track length
- About 3 feet (1 meter) per print
- Estimated walking speed
- About 3.5 to 4.5 miles per hour (5.6 to 7.2 kilometers per hour)







