Table 3. Descriptive statistics for each variable for the four float samples. SD is the standard deviation. Q1 is the first quartile (25% of teeth lie at or below Q1) and Q3 is the third quartile (75% of teeth lie at or below Q3).

Belgrade
(n=51)

Pungo River reject
(n=101)

Pungo River float
(n=102)

Yorktown
(n=193)

Geological age (Ma)
23.8

17.35

15.2

4.5

Length (mm)
Mean (SD)
Min, Max
median [Q1, Q3]

12.8 (2.8)
7.7, 19.0
12.4 [10.7, 15.1]

17.1 (3.7)
9.6, 26.9
17.2 [14.3, 19.0]

16.7 (3.3)
8.9, 24.4
17.2 [14.2, 18.6]

22.4 (4.7)
8.8, 35.5
22.1 [19.1, 25.4]

Ratio
Mean (SD)
Min, Max
median [Q1, Q3]

0.27 (0.03)
0.23, 0.33
0.26 [0.25, 0.29]

0.21 (0.04)
0.12, 0.35
0.21 [0.19, 0.23]

0.22 (0.03)
0.11, 0.30

0.22 [0.19, 0.24]

0.18 (0.04)

0.10, 0.27
0.18 [0.15, 0.20]

Number of serrations
Mean (SD)
Min, Max
median [Q1, Q3]

9.1 (1.2)
7.0, 11.0
9.0 [8.0, 10.0]

12.7 (1.9)
8.0, 18.0
13.0 [11.0, 14.0]

13.1 (1.9)
8.0, 18.0
13.0 [12.0, 14.0]

15.8 (3.0)
8.0, 28.0
16.0 [14.0, 17.0]

Avg. serr. width (mm)
Mean (SD)
Min, Max
median [Q1, Q3]

1.02 (0.18)
0.67, 1.34
1.01 [0.89, 1.16]

1.05 (0.16)
0.70, 1.57
1.04 [0.95, 1.15]

1.00 (0.15)
0.66, 1.45
1.00 [0.89, 1.10]

1.17 (0.14)
0.74, 1.60
1.17 [1.06, 1.27]

	Belgrade (n=51)	Pungo River reject (n=101)	Pungo River float (n=102)	Yorktown (n=193)
Geological age (Ma)	23.8	17.35	15.2	4.5
Length (mm) Mean (SD) Min, Max median [Q1, Q3]	12.8 (2.8) 7.7, 19.0 12.4 [10.7, 15.1]	17.1 (3.7) 9.6, 26.9 17.2 [14.3, 19.0]	16.7 (3.3) 8.9, 24.4 17.2 [14.2, 18.6]	22.4 (4.7) 8.8, 35.5 22.1 [19.1, 25.4]
Ratio Mean (SD) Min, Max median [Q1, Q3]	0.27 (0.03) 0.23, 0.33 0.26 [0.25, 0.29]	0.21 (0.04) 0.12, 0.35 0.21 [0.19, 0.23]	0.22 (0.03) 0.11, 0.30 0.22 [0.19, 0.24]	0.18 (0.04) 0.10, 0.27 0.18 [0.15, 0.20]
Number of serrations Mean (SD) Min, Max median [Q1, Q3]	9.1 (1.2) 7.0, 11.0 9.0 [8.0, 10.0]	12.7 (1.9) 8.0, 18.0 13.0 [11.0, 14.0]	13.1 (1.9) 8.0, 18.0 13.0 [12.0, 14.0]	15.8 (3.0) 8.0, 28.0 16.0 [14.0, 17.0]
Avg. serr. width (mm) Mean (SD) Min, Max median [Q1, Q3]	1.02 (0.18) 0.67, 1.34 1.01 [0.89, 1.16]	1.05 (0.16) 0.70, 1.57 1.04 [0.95, 1.15]	1.00 (0.15) 0.66, 1.45 1.00 [0.89, 1.10]	1.17 (0.14) 0.74, 1.60 1.17 [1.06, 1.27]