Skeletal remains in archaeological strata are often assumed to be of similar ages. Here we show that combined Sr and O isotope analyses can serve as a powerful tool for assessing fish provenance and even for identifying fossil fish teeth in archaeological contexts. For this purpose, we established a reference Sr and O isotope dataset of extant fish teeth from major water bodies in the Southern Levant. Fossil shark teeth were identified within Iron Age cultural layers dating to 8–9th century BCE in the City of David, Jerusalem, although the reason for their presence remains unclear. Their enameloid 87Sr/86Sr and δ18OPO4 values [0.7075 ± 0.0001 (1 SD, n = 7) and 19.6 ± 0.9‰ (1 SD, n = 6), respectively], are both much lower than values typical for modern marine sharks from the Mediterranean Sea [0.7092 and 22.5–24.6‰ (n = 2), respectively]. The sharks’ 87Sr/86Sr are also lower than those of rain- and groundwater as well as the main soil types in central Israel (≥0.7079). This indicates that these fossil sharks incorporated Sr (87Sr/86Sr ≈ 0.7075) from a marine habitat with values typical for Late Cretaceous seawater. This scenario is in line with the low shark enameloid δ18OPO4 values reflecting tooth formation in the warm tropical seawater of the Tethys Ocean. Age estimates using 87Sr/86Sr stratigraphy place these fossil shark teeth at around 80-million-years-old. This was further supported by their taxonomy and the high dentine apatite crystallinity, low organic carbon, high U and Nd contents, characteristics that are typical for fossil specimens, and different from those of archaeological Gilthead seabream (Sparus aurata) teeth from the same cultural layers and another Chalcolithic site (Gilat). Chalcolithic and Iron Age seabream enameloid has seawater-like 87Sr/86Sr of 0.7091 ± 0.0001 (1 SD, n = 6), as expected for modern marine fish. Fossil shark and archaeological Gilthead seabream teeth both preserve original, distinct enameloid 87Sr/86Sr and δ18OPO4 signatures reflecting their different aquatic habitats. Fifty percent of the analysed Gilthead seabream teeth derive from hypersaline seawater, indicating that these seabreams were exported from the hypersaline Bardawil Lagoon in Sinai (Egypt) to the Southern Levant since the Iron Age period and possibly even earlier.

中文翻译：

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锶和氧同位素分析揭示了黎凡特南部铁器时代地层中白垩纪晚期的鲨鱼牙齿

考古地层中的骨骼遗骸通常被认为具有相似的年代。在这里，我们表明结合 Sr 和 O 同位素分析可以作为评估鱼类来源甚至在考古环境中识别化石鱼牙齿的有力工具。为此，我们建立了黎凡特南部主要水体现存鱼牙的参考 Sr 和 O 同位素数据集。在耶路撒冷大卫城的公元前 8 至 9 世纪的铁器时代文化层中发现了鲨鱼牙齿化石，尽管它们存在的原因尚不清楚。它们的釉质 87Sr/86Sr 和 δ18OPO4 值 [0.7075 ± 0.0001 (1 SD, n = 7) 和 19.6 ± 0.9‰ (1 SD, n = 6)]，都远低于现代海洋鲨鱼的典型值地中海 [分别为 0.7092 和 22.5–24.6‰ (n = 2)]。鲨鱼的 87Sr/86Sr 也低于雨水和地下水以及以色列中部的主要土壤类型（≥0.7079）。这表明这些鲨鱼化石包含来自海洋栖息地的 Sr (87Sr/86Sr ≈ 0.7075)，具有晚白垩世海水的典型值。这种情况与反映特提斯洋温暖热带海水中牙齿形成的低鲨鱼釉质 δ18OPO4 值一致。使用 87Sr/86Sr 地层学的年龄估计将这些化石鲨鱼牙齿置于大约 8000 万年前。它们的分类学和高牙本质磷灰石结晶度、低有机碳、高 U 和 Nd 含量以及化石标本的典型特征进一步支持了这一点，与来自同一文化层和另一个铜石器遗址 (Gilat) 的考古学金头鲷 (Sparus aurata) 的牙齿不同。铜石时代和铁器时代鲷鱼釉质具有类似海水的 87Sr/86Sr 为 0.7091 ± 0.0001 (1 SD, n = 6)，正如现代海洋鱼类所预期的那样。鲨鱼化石和考古学的金头鲷牙齿都保留了原始的、独特的釉质 87Sr/86Sr 和 δ18OPO4 特征，反映了它们不同的水生栖息地。50% 的被分析的 Gilthead 鲷鱼牙齿来自高盐度海水，这表明这些鲷鱼自铁器时代以来就从西奈（埃及）的高盐度 Bardawil 泻湖出口到南黎凡特，甚至可能更早。正如现代海洋鱼类所预期的那样。鲨鱼化石和考古学的金头鲷牙齿都保留了原始的、独特的釉质 87Sr/86Sr 和 δ18OPO4 特征，反映了它们不同的水生栖息地。50% 的被分析的 Gilthead 鲷鱼牙齿来自高盐度海水，这表明这些鲷鱼自铁器时代以来就从西奈（埃及）的高盐度 Bardawil 泻湖出口到南黎凡特，甚至可能更早。正如现代海洋鱼类所预期的那样。鲨鱼化石和考古学的金头鲷牙齿都保留了原始的、独特的釉质 87Sr/86Sr 和 δ18OPO4 特征，反映了它们不同的水生栖息地。50% 的被分析的 Gilthead 鲷鱼牙齿来自高盐度海水，这表明这些鲷鱼自铁器时代以来就从西奈（埃及）的高盐度 Bardawil 泻湖出口到南黎凡特，甚至可能更早。