Figure 1.
Geographical location of the Kem Kem ichnofossils.
A, Location of Morocco (left corner of Africa map) and the Kem Kem outcrops shown in red, modified from Sereno and Larsson (2009) [56]. B, Close-up of Kem Kem localities located near the main ichnofossil site, Gara Sbaa (area shown as rectangle in A.)
Figure 2.
Geological context of the Kem Kem ichnofossils.
A, Simplified section through the Kem Kem sequence, modified from Martill et al. (2011). B, Debris-covered slope of Gara Sbaa, at the main collecting level for dinosaur footcasts. C, Main track horizon, marked by arrow. D, Ichnofossils collected on the same horizon (burrowing structures?) Scale bar equals 8 cm in D.
Table 1.
Measurements of tridactyl tracks from the Kem Kem beds.
Figure 3.
Traces of the lower Kem Kem beds.
A, B, Vertical burrows within thickly-bedded cross-bedded (A) and planar-bedded (B) sandstones. C, D, Heavily bored dinosaur bone fragment. The outer cortex of this bone shows deep longitudinal cracks and a loss of the most external bone (C) indicative of stage 4 weathering of Behrensmeyer (1978) [77]. Bone fragment also shows moderate amounts of abrasion. Borings, Cubiculum ornatus, are most prevalent in the bone interior (D). Hammer is 33 cm long in A; scale bar equals 5 cm in B and 5 cm in C and D.
Figure 4.
Horizontal meniscate and subvertical burrows of the upper Kem Kem beds.
These burrows are preserved as convex hyporelief most commonly observed together on the undersides of weathered-out siltstone and sandstones slabs. Coverage can reach nearly 100% of the slabs. Relative abundances vary from slabs dominated by horizontal meniscate burrows (A), to more even mixes (B), and slabs dominated by subvertical burrows (C). D, Close-up of mixed assemblage showing the oval to asymmetric cross-sections of the subvertical burrows. Scale bars equal 10 cm in A–C and 4 cm in D.
Figure 5.
Crawling and resting traces of the upper Kem Kem beds.
A–C, Lateral (A, B) and bedding plane (C) views of Conichnus conicus traces interpreted as sea anemone resting traces. Note the concave relief in plan view and the irregular planar to cross-bedded spreite in lateral view. Ripples and faint Scolicia trails are visible on the bedding surfaces in B. D, Large diameter burrow in plan view with one prominent and several less discrete Scolicia trails. The large burrow could represent the opening of a lungfish burrow or alternatively could represent a differently preserved Conichnus. E, Crawling trace leading to a vertical burrow. The alternating series of bumps of the proximal portion to burrow is reminiscent of Scerichnites. Scale bars equal 4 cm in A, B and D, and 9 cm in C and E.
Figure 6.
Examples of small ichnofossils from the Kem Kem sequence.
A, UCRC PI714. B, coprolite FSAC-KK 935. C, FSAC-KK 936. D, FSAC-KK 2871 and E, FSAC-KK 2838. See Table 1 for institutional abbreviations. Scale bars equal 5 cm in A and 5 cm in B–E.
Figure 7.
Examples of dinosaur footprints found at Gara Sbaa.
A, B, Natural casts of theropod tracks (not collected). C, True track of a theropod (not collected). D, Superimposed natural casts of theropod tracks (not collected). Scale bars equal 8 cm in B–D.
Figure 8.
Theropod footprints at Gara Sbaa.
A, Large isolated natural cast of theropod track (not collected). B, Relatively poorly defined natural cast of a theropod track (not collected). Scale bar equals 10 cm in B.
Figure 9.
Removal of a plaster cast of a probable theropod footprint.
A, Removal of a plaster cast left behind by the 1995 University of Chicago expedition. B, Appearance of the track after removal of the plaster. C, Plaster cast, now catalogued as FSAC-KK 12. Scale bar equals 8 cm in B.
Figure 10.
Ichnomorphological diversity of theropod tracks.
A, UCRC I 160. B, UCRC I 252. C, UCRC I 260. D, UCRC I 258. E, UCRC I 253. F, UCRC I 259. G, Image of the block that contained UCRC I 260 identified during 2008 UCD/UoP/FSAC expedition. H, Image of the block that contained UCRC I 258, identified during 2008 UCD/UoP/FSAC expedition. Scale bars equal 10 cm in A-F and 8 cm in G and H.
Figure 11.
A, UCRC I 250. B, UCRC I 251. C, UCRC I 256. D, UCRC I 261. E, UCRC I 262. F, UCRC I 264. G, H, UCRC I 255 in (G) ventral view and (H) dorsal view. Scale bar equals 20 cm.
Figure 12.
Likely digit morphology of selected Kem Kem dinosaur tracks.
A, UCRC I 252. Track photo shown in Figure 10B. B, UCRC I 260. Track photo shown in Figure 10C. C, UCRC I 258. Track photo shown in Figure 10D. D, UCRC I 259. Track photo shown in Figure 10F. E, UCRC I 250. Track photo shown in Figure 11A. F, UCRC I 256. Track photo shown in Figure 11C. G, UCRC I 262. Track photo shown in Figure 11E. H, UCRC I 264. Track photo shown in Figure 11F. I, UCRC I 263. Track photo shown in Figure 16B. Preserved digit impressions in black, track outline in grey. Outlines not to scale; see Figures 10, 11 and 16 for size of specimens.
Figure 13.
Dinosaur tracks: Width/Length and Digit IV/Maximum length graphs.
Measurements in mm.
Figure 14.
Sauropod-manus print cast (UCRC I 1995).
Natural cast of sauropod left manus track in dorsal (A), anterior (B), and ventral views (C). Note the straight grooved sides of the track in anterior view (B), the five lobes corresponding to the tightly bound digits I–V, and the absence of any divergent phalanges or unguals. Scale bar equals 10 cm.
Figure 15.
Isolated neosauropod track (UCRC I 173).
A, Vental view. B, Anterior view, arrows showing claw marks. Scale bar equals 10
Figure 16.
A, Definitive ornithopod track (not collected). B, Possible ornithopod track (UCRC I 263). Measurements of the track in (A) are provided in the text. Scale bar equals 10 cm in B.