Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon ((14)C) in the atmosphere. Hair from other primates, including two other C ages consistent with known dates, further suggesting that diet is not the cause for the age discrepancy.As a result, organic material formed during or after this period may be radiocarbon-dated using the abrupt rise and steady fall of the atmospheric (14)C concentration known as the bomb-curve. The most likely explanation is that the date of museum accession, which we used as the known age of the sample, does not reflect the date of death.(14)C dating of tissues has applications to stable isotope (paleo)ecology and wildlife forensics. Using the tusk lengths and growth rates for R37 and Misha, we calculate the time represented in the tusks to be 28.0 and 14.8 y, respectively (C ages from tusks that formed between 19, particularly from male tusks and tusks that capture multiple ontogenetic stages, would elucidate variation in tusk growth rate as a function of sex and age.We use data from 41 additional samples to determine growth rates of tusks, molars, and hair, which improve interpretations of serial stable isotope data for (paleo)ecological studies. = 5) and an upper (n =3) canine of an individual, presumed to be a juvenile or young adult based on canine shape and size, give linear growth rates of 3.35 ± 0.25 cm/y and 1.94 ± 0.31 cm/y, respectively (). (22) measured lower canine growth rates in two female hippos from the Toledo Zoo by notching the tooth at the gum line and measuring the distance from the gum line the following year. Several studies have explored the use of radiocarbon to date tusk ivory (4, 12, 13) but offer only limited data and, in some cases, lower precision than accelerator mass spectrometry (AMS) methods (13). Forensics research to determine year of birth has focused primarily on human tooth enamel and dentin (6–10), although proteins in the crystalline portions of eye lenses also provide accurate birth-year estimates (11).
Here we use animal and plant tissues of known ages to expand significantly on previous studies in the number of samples and tissue types to show that from 1955 to the present C dating based on results from 29 apatite, collagen, keratin, soft tissue, and plant samples. C dating can also be used to calculate the time interval represented in periodic histological structures in dental tissues (i.e., perikymata), which in turn may be used as chronometers in fossil teeth. We use data from 41 additional samples to determine growth rates of tusks, molars, and hair, which improve interpretations of serial stable isotope data for (paleo)ecological studies. Atmospheric through air–sea exchange and subsequent vertical mixing and becomes part of the biologically available dissolved inorganic carbon pool. Bomb-curve C dating of confiscated animal tissues (e.g., ivory statues) can be used to determine whether trade of the item is legal, because many Convention of International Trade of Endangered Species restrictions are based on the age of the tissue, and thus can serve as a powerful forensic tool to combat illegal trade in animal parts. This occurs naturally from secondary neutron flux generated by cosmic rays and anthropogenically by high neutron flux from nuclear fission in bombs or, to a lesser degree, nuclear reactors.