In 2013 we presented a model for identifying nursing behavior from primate teeth based on rapid postnatal concentration changes in the non-essential trace element barium. Here we leverage the permanent neonatal (birth) line in the enamel of several dozen primate M1 cusps to compare pre- and postnatal trends in barium, zinc, strontium, and oxygen, as each element is believed to evince developmental patterning. Barium and zinc are the most consistent biomarkers of nursing initiation; a majority of M1 cusps shows concentration increases from prenatal to postnatal enamel, whereas strontium shows decreases or no change with similar frequency. Exceptions to the pattern of barium increase occurred in cusps that had been mineralizing for less than three weeks, suggesting that subsequent enamel maturation has only a minor impact on detecting real time events. Oxygen isotope compositions (δ¹⁸O) show rapid and marked fluctuations (∼1–2‰) within two weeks of birth in 93% of M1 cusps (n = 27/29). This is likely due to measurements of hypomineralized perinatal enamel and physiological changes in the body water of newborn infants. Ongoing work integrating elemental concentration gradients with isotopic variation will help establish the degree to which milk intake may cause elevated δ¹⁸O in teeth. We show that chemical identification of pre-to postnatal transitions may be robust to slight planar deviations that commonly obscure growth increments under light microscopy, and could help validate the identification of potential neonatal lines, making this approach a useful complement to bioarchaeological studies and public health investigations.

2013 年，我们提出了一种基于非必需微量元素钡的产后快速浓度变化来识别灵长类动物牙齿护理行为的模型。在这里，我们利用几十个灵长类动物 M1 牙釉质中的永久性新生儿（出生）线来比较钡、锌、锶和氧的出生前和出生后趋势，因为每个元素都被认为表明发育模式。钡和锌是护理开始的最一致的生物标志物；大多数 M1 牙尖显示从产前到产后牙釉质的浓度增加，而锶显示减少或没有变化，频率相似。钡增加模式的例外发生在矿化不到三周的尖端，表明随后的牙釉质成熟对检测实时事件的影响很小。氧同位素组成（δ¹⁸ O) 在 93% 的 M1 牙尖 (n = 27/29) 中在出生两周内显示出快速和显着的波动 (~1-2‰)。这可能是由于对围产期牙釉质的低矿化和新生儿体内水分的生理变化的测量。正在进行的将元素浓度梯度与同位素变化相结合的工作将有助于确定牛奶摄入可能导致牙齿中 δ ¹⁸ O 升高的程度。我们表明，产前到产后转变的化学鉴定可能对轻微的平面偏差具有鲁棒性，这些偏差通常会在光学显微镜下掩盖生长增量，并且可以帮助验证潜在新生儿系的鉴定，使这种方法成为生物考古研究和公共卫生的有用补充调查。