1. These geological formations have not been dated radiometrically, but scientists have used biostratigraphy to estimate their age.

2. Radiometrically Calibrated light sources are carefully characterized to deliver a known quantity of light with very low uncertainty

3. The Antlers Formation contains fossils of Deinonychus and Tenontosaurus, two dinosaur genera also found in the Cloverly Formation, which has been radiometrically dated to the Aptian and Albian stages, suggesting a similar age for the Antlers.