supplementary materials for - science advances · beta 463276 23190 80 organic mud nps 2017...

advances.sciencemag.org/cgi/content/full/4/4/eaar7621/DC1

Supplementary Materials for

Footprints preserve terminal Pleistocene hunt? Human-sloth

interactions in North America

David Bustos, Jackson Jakeway, Tommy M. Urban, Vance T. Holliday, Brendan Fenerty,

David A. Raichlen, Marcin Budka, Sally C. Reynolds, Bruce D. Allen, David W. Love,

Vincent L. Santucci, Daniel Odess, Patrick Willey, H. Gregory McDonald, Matthew R. Bennett

Published 25 April 2018, Sci. Adv. 4, eaar7621 (2018)

DOI: 10.1126/sciadv.aar7621

This PDF file includes:

fig. S1. Bluff section on the western edge of Alkali Flat adjacent to the study site.

fig. S2. Cross sections through tracks and geotenches.

fig. S3. Map of part of the study site.

fig. S4. Map of excavated tracks in part of the study site.

fig. S5. Orthorectified mosaic of part of the study site.

fig. S6. 3D point cloud models of excavated human tracks.

fig. S7. 3D point cloud models of excavated tracks.



fig. S10. Size and age estimations for excavated and unexcavated elongated tracks

at and in the vicinity of the study site.

fig. S11. (A) Orthorectified mosaic of part of the study site showing two “flailing

circles” as well as sloth and human composite tracks. (B) Interpretation of

trackway trajectories are based on ghost and excavated tracks.

fig. S12. Tortuosity of sloth tracks in presence/absence of human tracks.

table S1. Radiocarbon and OSL dates from WHSA.

table S2. Measurements and interpretations of excavated tracks at WHSA.

fig. S1. Bluff section on the western edge of Alkali Flat adjacent to the study site. See Figure 1 for approximate

location.

fig. S2. Cross sections through tracks and geotenches. A. Cross-section through a human track showing the

organic rich sediments below. B. Cross section through a superimposed sloth and human track. Not the fluid-

escape structure below the heel strike of the human track. C. Geo-trench through a sloth track showing the infill

and the fulid escape structures beneath the plantar surface. Dates are uncalibrated radiocarbon ages. Scales in

centimeters. Fm = massive silts/clays; Fl= laminated silts/clays; Pg = organic rich sediment verging to peat; Sm =

massive sands; Sh = horizontally stratified sands; Hy = hydro-fractures; (cry) = crystals; (m) = mottling; (r) root

traces; (i) = indurated horizons; Fr = root fragment/traces.

fig. S3. Map of part of the study site. The map shows sloth and human tracks as well as track density across the

whole site (inset). Note the non-linear sloth trackways and sudden changes of direction. “Flailing circles” occur

only in association with human tracks.

fig. S4. Map of excavated tracks in part of the study site.

fig. S5. Orthorectified mosaic of part of the study site. Note the sudden direction change in the sloth trackway

indicated by the arrowed line.

fig. S6. 3D point cloud models of excavated human tracks. See fig. S6 for locations and table S2 for print

measurements and interpretations. The ruler is 300 mm long.

fig. S7. 3D point cloud models of excavated tracks. See fig. S6 for locations and table S2 for print measurements

and interpretations. The ruler is 300 mm long.

fig. S8. 3D point cloud models of excavated tracks. See fig. S6 for locations and table S2 for print dimensions and

interpretations. The ruler is 300 mm long.

fig. S9. 3D point cloud models of excavated tracks. See fig. S6 for locations and table S2 for print dimensions and

interpretations. The ruler is 300 mm long.

fig. S10. Size and age estimations for excavated and unexcavated elongated tracks at and in the vicinity of the

study site. Unexcavated elongated tracks could be either human or sloth. The best fit curve is based on a von

Bertalanffy. Growth Curve 𝑦 = 306.05(1 − 0.65859−0.08163𝑥).

fig. S11. (A) Orthorectified mosaic of part of the study site showing two “flailing circles” as well as sloth and

human composite tracks. (B) Interpretation of trackway trajectories are based on ghost and excavated tracks.

fig. S12. Tortuosity of sloth tracks in presence/absence of human tracks.Tortuosity is measured as a ratio of

direct length (DL) to cumulative track length (TL). Sloth tracks numbered >T10 and are all at or in the vicinity of

the study site. Tracks < T10 are from other Alkali Flat areas without human tracks. The tortuosity ratio is plotted

for each track (yellow dots) and selected trackways are shown either side of the plotted values to illustrate the actual

trackway itself and the location of the human tracks. The box plots (bottom) show the range of tortuosity for

trackways with and without associated human tracks.

table S1. Radiocarbon and OSL dates from WHSA. For unpublished dates, the Principal Investigator (PI) is

indicated. NPS = National Park Service. All dates are uncalibrated.

Code Date (C14 Years BP) Error Material Publication or PI

Beta 463274 100 30 Plant Material NPS 2017

Beta 463275 140 30 Plant Material NPS 2017

AA109165 10223 29 Palustrine Mud Holliday 2017


Beta 386791 13580 50 Organic Mud NPS 2015

Beta 216105 15660 50 Ostracods Allen et al. (5)

Beta 328288 15670 60 Macrophytes NPS 2014




AA103021A 18620 110 Seeds Holliday 2014

AA110050 18,666 82 Palustrine Mud Holliday 2017

AA103022B 18710 120 Seeds Holliday 2014

AA103024D 18740 150 Seeds Holliday 2014

AA103023C 18900 120 Seeds Holliday 2014

Beta 202927 19430 70 Macrophytes Allen et al. (5)








Beta 3911942 21480 80 Shell NPS 2015



Beta 206641 22800 130 Charcoal Allen et al. (5)





Beta 216109 24420 190 Charcoal Allen et al. (5)




Beta 339424 28330 160 Dolomite NPS 2014



Beta 339423 30300 180 Dolomite NPS 2014










Beta 386793 35160 270 Charcoal NPS 2015


Alkali Flat/BP2 WS/9 26130 1920 OSL NPS 2016

Alkali Flat/BP3 WS/13.5 41350 2650 OSL NPS 2016

table S2. Measurements and interpretations of excavated tracks at WHSA. See fig. S6 for location of tracks.

Track Length (mm) Width (mm) Comment/Interpretation

TE-A-1 291.9 103.2 RF, Adult Human TE-A-2 283.2 88.5 LF, Adult Human TE-A-3 222.8 97.1 LF, Adult Human TE-A-4 RF, Adult Human TE-A-5 210.3 88.5 RF, Human TE-A-6 220.1 96.6 RF, Human TE-A-7 218.2 83.1 RF, Human TE-A-8 214.5 116 LF, Human TE-A-9 218.7 83 RF, Human TE-A-10 220.1 96.6 LF, Human TE-A-11 346 203.6 Irregular probably human? TE-A-12 219.8 81.8 RF, Human TE-A-13 283.75 110.1 LF, Human TE-A-14 Uncertain TE-A-15 Uncertain TE-A-16 385.2 195 LF, Sloth TE-A-17 347.5 128.8 RF, Sloth [possible human trace] TE-A-18 322.2(Human: 152.3) 159(73) LF, Sloth + Human TE-A-19 213.4 101.7 LH, Human TE-A-20 381.7(Human: 236.7) 135.9(78.7) RF, Sloth + RH Human TE-A-21 270.9 150.9 Human? Irregular TE-A-22 133.7 89 Irregular mark TE-A-23 140.7 76.4 Human toes? TE-A-24 263.7 95.6 RH, Sloth, manus? TE-A-25 Uncertain TE-A-26 145. 78.5 Human toes? TE-A-27 222.8 102.2 RF, Human TE-A-28 125 65 Impression, unknown origin TE-A-29 520 243.5 RF, Sloth TE-A-30 400 296.6 LF, Sloth, irregular TE-A-31 222.9 98.8 RF, Human TE-A-32 214 90.1 LF, Human TE-A-33 311.2 195.6 LF, Sloth, irregular TE-A-34 Uncertain TE-A-35 159.9 69.1 Sloth, irregular pes, claw marks visible TE-A-36 127 63.6 Sloth, irregular pes, claw marks visible TE-A-37 246.3 179.8 Sloth, irregular pes, claw marks visible TE-A-38 346.9 139.1 RF, Sloth TE-A-39 154.2 78.4 Sloth, irregular pes, claw marks visible TE-A-40 247(82.5) 237(81.5) Sloth? Two circular impressions TE-A-41 233 85 Sloth, pes, three claws marks visible TE-A-42 156.2 106.1 Sloth pes track, claws visible TE-A-43 247.6 159.7 Uncertain TE-A-44 412.7(Human: 215) 183.4(91.3) LF, Sloth + LH Human TE-A-45 404.1(Human:196.7) 200.5(87.1) RF, Sloth + RH Human TE-A-46 409.4(Human: 240) 210(114) RF, Sloth + Human TE-A-47 452.9 212.3 Human + Sloth, irregular

LF, human = left foot human, RF, human = right foot human; LF, sloth = left foot sloth, RF, sloth = right foot sloth

supplementary materials for - science advances · beta 463276 23190 80 organic mud nps 2017...

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