An international team of scientists developed a novel technique for precisely ascertaining the age of fossil-bearing rock strata by directly analyzing dinosaur eggshells. This approach has become a reliable alternative to conventional methods that rely on surrounding minerals, which are not present at every locale. An artistic depiction shows a newly hatched dinosaur, resembling a troodontid, amongst the fragments of its eggshell. When such shells became interred in ancient soil, they interacted with meteoric waters, which caused the incorporation of uranium into the calcite crystals. Author: Eva Utsukiyohei. The research, published in the journal Communications Earth & Environment, was led by Dr. Ryan Tucker from Stellenbosch University. Instead of examining surrounding minerals or bones, researchers concentrated on the eggshell itself. Utilizing an advanced uranium-lead (U-Pb) dating procedure, the group measured the microscopic amounts of uranium and lead “trapped” within the calcite crystal structure of the shell. These radioactive elements decay at a known rate, functioning as internal chronometers indicating when the eggs were buried. The technique was validated on specimens from Utah (USA) and the Gobi Desert (Mongolia). Findings demonstrated that the shell’s age can be determined with an accuracy nearing five percent when compared to dating via volcanic ash layers. In Mongolia, the team accomplished the first direct determination of the age of a renowned site featuring dinosaur eggs and nests—approximately 75 million years old. “The calcite of eggshell is a surprisingly versatile material,” states Dr. Tucker. “It furnishes us an innovative means to date fossil sites lacking volcanic layers, which has posed a challenge for paleontology for decades.” Study co-author, Lindsay Zanno from the University of North Carolina, called the direct dating of fossils a “paleontologist’s aspiration.” According to her, the new procedure will help solve mysteries of dinosaur evolution that previously seemed insurmountable. Rutab.net
About the Author
