Carbon isotope used radiocarbon dating
These, together with many other remarkable concordances between samples from different fossils, geographic regions and stratigraphic positions make random contamination as origin of the C-14 unlikely". She started a firestorm of controversy in 20 when she reported that she had sequenced proteins in the dinosaur bone.
Critics charged that the findings were mistaken or that what she called soft tissue was really biofilm produced by bacteria that had entered from outside the bone.
That included protecting the samples, avoiding cracked areas in the bones, and meticulous pre-cleaning of the samples with chemicals to remove possible contaminants.
Knowing that small concentrations of collagen can attract contamination, they compared precision Accelerator Mass Spectrometry (AMS) tests of collagen and bioapatite (hard carbonate bone mineral) with conventional counting methods of large bone fragments from the same dinosaurs. Mary Schweitzer, associate professor of marine, earth, and atmospheric sciences at North Carolina State University, surprised scientists in 2005 when she reported finding soft tissue in dinosaur bones.
The latter method was developed for problematic (i.e.
Collagen was extracted, its quality assessed using %C, %N and C: N, and δN values from the two laboratories.
In addition, there are trace amounts of the unstable isotope carbon-14 (14C) on Earth.
Carbon-14 has a relatively short half-life of 5730 years, meaning that the amount of carbon-14 in a sample is halved over the course of 5730 years due to radioactive decay.
Since dinosaurs are thought to be over 65 million years old, the news is stunning - and more than some can tolerate.
After the AOGS-AGU conference in Singapore, the abstract was removed from the conference website by two chairmen because they could not accept the findings.