Imprints of domesticated pearl millet (Pennisetum glaucum (L.) R. Br.) spikelets, observed as temper in ceramics dating to the third millennium BC, provide the earliest evidence for the cultivation and domestication process of this crop in northern Mali. Additional sherds from the same region dating to the fifth and fourth millennium BC were examined and found to have pearl millet chaff with wild morphologies. In addition to studying sherds by stereomicroscopy and subjecting surface casts to scanning electron microscopy (SEM), we also deployed X-ray microcomputed tomography (microCT) on eleven sherds. This significantly augmented the total dataset of archaeological pearl millet chaff remains from which to document the use of the wild pearl millet as ceramic temper and the evolution of its morphology over time. Grain sizes were also estimated from spikelets preserved in the ceramics. Altogether, we are now able to chart the evolution of domesticated pearl millet in western Africa using three characteristics: the evolution of nonshattering stalked involucres; the appearance of multiple spikelet involucres, usually paired spikelets; and the increase in grain size. By the fourth millennium BC, average grain breadth had increased by 28%, although spikelet features otherwise resemble the wild type. In the third millennium BC, the average width of seeds is 38% greater than that of wild seeds, while other qualitative features of domestication are indicated by the presence of paired spikelets and the appearance of nondehiscent, stalked involucres. Nonshattering spikelets had probably become fixed by around 2000 BC, while increases in average grain size continued into the second millennium BC. These data now provide a robust sequence for the morphological evolution of domesticated pearl millet, the first indigenous crop domesticated in western Africa.

驯化珍珠粟（Pennisetum glaucum (L.) R. Br.）小穗的印记是在公元前三千年的陶瓷中观察到的，为马里北部这种作物的种植和驯化过程提供了最早的证据。对来自同一地区的公元前五千年和四千年的其他陶片进行了检查，发现含有野生形态的珍珠粟谷壳。除了通过立体显微镜研究碎片并对表面铸件进行扫描电子显微镜 (SEM) 检测之外，我们还在 11 个碎片上部署了 X 射线微计算机断层扫描 (microCT)。这显着增加了考古珍珠粟谷壳遗骸的总数据集，从中记录了野生珍珠粟作为陶瓷回火的使用及其形态随时间的演变。还根据陶瓷中保存的小穗来估计晶粒尺寸。总而言之，我们现在能够利用三个特征来描绘西非驯化珍珠粟的进化：不破碎的有柄总苞的进化；出现多个小穗总苞，通常是成对的小穗；和晶粒尺寸的增加。到公元前四千年，平均谷粒宽度增加了 28%，尽管小穗特征在其他方面与野生型相似。在公元前三千年，种子的平均宽度比野生种子大 38%，而驯化的其他定性特征则表现为成对小穗的存在和不开裂、有柄总苞的出现。不破碎的小穗可能在公元前 2000 年左右就已经固定，而平均颗粒尺寸的增加一直持续到公元前第二个千年。这些数据现在为驯化珍珠粟的形态进化提供了可靠的序列，珍珠粟是西非第一个驯化的本土作物。