Molecular level carbon-14 dating is the isolation of specific classes of molecules for their carbon-14 dating by accelerator mass spectrometry (AMS). Complex matrices such as fossil bone are difficult to date due to their extreme chemical heterogeneity. By isolating individual amino acids, contaminants (humates) are removed and crystalline amino acids result. Bones with gte0.1-0. 2% nitrogen and collagenous compositions can be dated accurately because structural collagen is present; contaminants are removable with XAD resin. Bones with lte0.1% nitrogen and noncollagenous compositions yield dates hundreds to thousands of years too young because most of the preserved organic matter is exogenous. Accelerator carbon-14 dates on collagenous and noncollagenous bones are not comparable due to intrinsic dating inaccuracies. AMS carbon-14 dating of amino acids demonstrated the following: 1) post 10,800 year ages for North American megafauna are due to sample contamination, not Holocene ages on extinct fauna; 2) a Clovis age (10,900 years) was established for a human fossil from the Anzick site, Montana; 3) Holocene ages cannot be established absolutely for many North American human fossils because the bones were noncollagenous; 4) accurate ages are attainable on vertebrate fossils as small as passerine birds from Pacific Islands localities; 5) well preserved bones are datable without their destruction by extracting protein with water at high temperatures; and 6) stratigraphic anomalies to 45,000 years in European Upper Paleolithic rock shelters are recognizable by dating bone directly.