The Dinosaur Surveyors

A 4.163Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

Eastern Wyoming, Almost South Dakota. For the last 15 years Dr. Art Chadwick, with the help of hundreds of students and volunteers, has been compiling a 3D digital picture of a massive 5000+ acre Upper Cretaceous period dinosaur bone bed at the Hanson Research Station in remote Eastern Wyoming.

Unlike typical fossil beds, this meter-thick deposit of bones is a mixture from an estimated 10,000+ complete dinosaurs.

The remains of all the dinosaurs are mixed together in a tightly packed, 10% by volume "soup," with larger bones at the bottom, covered with claystone and overlaid with sandstone.

Typically more than 50 bones are found in every square meter of excavated quarry. Bone and tooth sizes range from fingernail sized teeth and vertebrae to torso sized femur and Triceratops skulls.

A possible explanation for this bed of mixed bones is:
A single catastrophic event killed all of the dinosaurs at once, depositing their bodies in a lake to decompose. Subsequently a natural dam forming the lake washed out, mixing and transporting the bones to their current location in a well preserved fossil bed.

Over 2,000 fossils are recovered each year during a 1-month field season. The 3-D location and axis of each bone are recorded using RTK GPS. Subsequently a 3-D virtual bone image is captured for every fossil. Finally each 3-D visual bone model is placed into a database and a browseable Virtual Bone Bed.

With the click of a mouse, you can pan and zoom through the Virtual Bone Bed, highlighting bones by type or species. There is hope that this model might lead to a better understanding of how these dinosaurs became part of the fossil record (this study is called Taphonomy.)

Because of the huge expanse of this fossil bed and a desire to tie all of the specimens together in one uniform coordinate system, it was determined that RTK GPS acquired UTM coordinates would be the best way to relate the specimens.

Over the last decade this RTK-GPS based survey method has proven to be an excellent choice and has resulted in a unique and innovative 3D bone survey, library and Virtual Bone Bed.

How to Survey and Build a Virtual Dinosaur Bone Bed
Here is how specimens are converted from buried bones to high definition virtual bones in a unified database:

1. A single solar powered GPS base station (with an OPUS derived datum) provides coordinate control for the entire site. WiFi mesh repeaters connect all of the quarry sites allowing field data to be transferred to the cloud as it is collected.
2. Each bone is isolated, stabilized, assigned a unique tracking number and photographed in its quarry location.
3. The endpoints, outline and axis of each bone are recorded using RTK GPS.
4. The GPS points produce fiduciary marks for registering the bone in the virtual bed.
5. The specimen is transported back to the lab, where a 360 degree, 3-D high resolution model of the bone is produced. (You can view this bone in a high-resolution 360 rotating view by visiting and searching for specimen number 5331.)
6. Finally the 3D image is registered in the virtual bone bed.

Traditionally paleontologists have relied on hand taped offsets from datum strings, field notes, photos and hand drawn maps to record bone spatial information. RTK GPS is much faster and when implemented with good control and field techniques, results in an accurate photo-realistic Virtual Bone Bed.

Over the past 15 seasons, 16,200 bones and teeth have been mapped using RTK GPS at the Hanson Research Station. All of the specimens from previous years are available for online inspection today at

If you have an interest in Dinosaur Surveying or just volunteering in an active quarry you are welcome to participate. All interested participants are welcomed regardless of experience. Field season starts the first of June every year, details are available at This just may be the most fun you can possibly have with RTK GPS!
Mark Silver is an Electrical Engineer, a topographic map collector, and a long time vendor of GPS products.

A 4.163Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE