Table ED2.

Length and thickness range and average size of scalloped-sphere phytoliths identified in this study. Based on Piperno et al. (2000), we consider scalloped spheres longer than 72 μm or thicker than 59 μm as coming from domestic varieties of Cucurbita sp.

Site	Date cal. yr. B.P.	Length (μm)	Thickness (μm)	Domesticated	Depth
Isla del Tesoro	7839-7020	80,361	59,804	Yes	170-180 cm
575	10155-9632	82,524	58,318	Yes	270-280 cm
		72,804	65,178	Yes
		72,775	54,214	Yes
519	6443-6380	77,884	55,212	Yes	100 cm
		82,418	65,752	Yes
		75,938	54,452	Yes
		75,296	57,433	Yes
FIN-12	4785-4424	81.19	55,162	Yes	90-95 cm
		80,653	60,988	Yes
		61,005	45,635	No
		77,871	67,843	Yes
La Chacra	6707-5826	83,697	59,724	Yes	80-84 cm
		78,895	52,993	Yes
	7350-6945	75,789	56,754	Yes	108-113 cm
	8530-7965	63,119	41,238	No	140-145 cm
	9212-8665	75,419	65,484	Yes	160-165 cm
Isla Manechi	3319-3007	74.28	52.33	Yes	25 cm
		72.7	57.57	Yes
		78.49	50.79	Yes
		81.34	48.89	Yes
		70.1	45.38	Yes
		78.12	64.79	Yes
		61.29	51	No
		69.22	56.6	No
		61.78	46.56	No
		59.96	49.13	No
	4957-4728	68.67	54.95	No	55 cm
		57.22	40.23	No
		70.53	49.5	No
		63.21	49.51	No
		70.59	44.29	No
		81.74	66.85	Yes
		72.76	58.61	Yes
	5288-4965	74.27	57.12	Yes	85 cm
		74.53	45.13	Yes
		58.98	44.15	No
		81.95	56.8	Yes
		68.1	59.06	No
		66.84	55.37	No
		76.91	49.26	Yes
		74.69	47.15	Yes
		84.72	60.19	Yes
	10284-10196	78,173	66,108	Yes	105 cm
		84,996	67,836	Yes
		72,601	54,422	Yes
		64,201	50,158	No
		84,858	64,479	Yes
		68.44	57.37	No
		81.82	60.62	Yes
		86.81	63.17	Yes
	10664-10380	60.46	51.16	No	145 cm