Figure 1.
Geographic and geological setting of the study area.
(A) Geological map of the southern Pyrenees with Tremp Formation outcrops and location of tracksites and measured sections (modified from López-Martínez and Vicens [26]). (B) Geological map of the Isona sector (enlarged area in A) and location of tracksites and measured sections (modified from Riera et al. [6]). Numbers (tracksites): 1, Fornons 3 and Dolor 2; 2, Serraduy Norte and Serraduy Sur; 3, Iscles-1, Iscles-2, Iscles-3, Iscles-4, and Iscles-5; 4, Areny 1; 5, Sapeira-1 and Sapeira-2; 6, La Mata del Viudà; 7, Moror A and Moror B; 8, La Massana; 9, Fumanya; 10, Cingles del Boixader; 11, La Pleta Resclosa and La Pleta Nord; 12, Camí de les Planes and Serrat de Santó; 13, Costa Roia; 14, Torrent de Carant; 15, Serrat de Sanguin; 16, Orcau-2; 17, Orcau-4; 18, Barranc de Torrebilles-5; 19, Basturs Poble; 20, La Llau de la Costa; 21, Tossal del Gassó; 22, Masia de Ramon Petjades; 23, Barranc de Guixers-1 and Barranc de Guixers-2; 24, Barranc de Guixers-3. See abbreviations for measured sections in ”Methodology” section.
Figure 3.
Track occurrence in the Tremp Formation.
(A–D) Underneath views of overhanging ledges in the Iscles-3, Cingles del Boixader, La Mata del Viudà, and Masia de Ramon Petjades localities, respectively. (E and F) Cross-sectional outcrop views in the La Pleta Nord and Serraduy Sur localities, respectively. (G and H) Plan view outcrops in the Areny 1 and La Llau de la Costa localities, respectively. Scale bar: 15 cm; hammer length is about 33 cm. Arrows indicate the position of some tracks.
Table 1.
Track localities and sedimentary environments of dinosaur track localities in the Tremp Formation.
Figure 2.
Sedimentary architecture in outcrops of the main track localities of the Tremp Formation.
(A–G) Iscles-3, Masia de Ramon Petjades, Costa Roia, Serraduy Sur, La Llau de la Costa, Cingles del Boixader and La Mata del Viudà sites, respectively.
Figure 4.
Track preservation in the Tremp Formation.
(A) Footprints preserved as undetermined sandstone moulds on irregular surfaces, representing “dinoturbated” track levels. (B–E) Footprints impressed in the muddy floodplain and preserved as natural casts (convex hyporeliefs) at the base of the sandstone channel beds in the Serrat de Sanguin, La Pleta Nord, Sapeira-1, and Serraduy Sur localities, respectively. (F–I) Footprints impressed in accretion surfaces (mudstone) and preserved within the sandstone bed in the Serraduy Norte, La Pleta Nord, La Pleta Resclosa, and Cingles del Boixader localities, respectively. (J) Footprint preserved as an isolated sandstone cast within the mudstone of the floodplain in the Serrat de Sanguin locality. Numbers in A indicate tracks. Scale bars: 5 cm (in D), 10 cm (in C, H, and I), 15 cm (in E, and F), and 20 cm (in B and J); scale tape in A and G is in cm. Arrows indicate the position of some tracks.
Figure 5.
Footprint morphologies and characteristics.
(A, C) Hadrosaur pedal tracks (MCD-5140 and MCD-5142, respectively) from the La Llau de la Costa locality. (B) Hadrosaur pedal track from the Iscles-3 locality. (D) Hadrosaur pedal track (uncollected) from the Barranc de Guixers-1 locality. Note the impression of the distal ungual phalanx (arrow). (E) Hadrosaur pedal track (uncollected) from the Masia de Ramon Petjades locality. Note the triangular-shaped plantar impression produced by the heel pad (arrow). (F) Striae or scale scratch lines (arrow) on the margins of a toe in the MPZ 2012/829 cast from the Serraduy Norte locality. (G) Sauropod pedal track (cast) from the Barranc de Guixers-2 locality. Scale bar: 15 cm (in A–E); 5 cm (in F); scale tape in G in cm.
Figure 6.
Mapping of some of the main hadrosaur track localities in the Tremp Formation.
(A–D) Cingles del Boixader, Masia de Ramon Petjades, La Mata del Viudà, and La Llau de la Costa localities, respectively. Scale bar: 50 cm.
Figure 7.
Hadrosaur pedal footprints from the Tremp Formation (white outlines) and other Maastrichtian formations (unfilled outlines) from North America and Asia.
(A, C, D) Negative hyporeliefs from the La Llau de la Costa locality (MCD-5140, MCD-5141, MCD-5142, respectively). (B and O) Casts from the Serraduy Norte locality (MPZ 2012/829 and MPZ 2012/827, respectively). (E and F) Casts from the Cingles del Boixader locality (IPS-63661/CB1-CB3). (G) Cast from Serraduy Sur locality (MPZ 2012/828). (H) Cast from the Serrat de Sanguin locality (MCD-5159). (I and K) Casts from the Masia de Ramon Petjades locality (MRP-6, MRP-8). (J) Cast from the Iscles-3 locality (I3–5). (L) Manus-pes casts from the La Mata del Viudà locality (MV-3 and MV-2, respectively). (M and N) Casts from the Camí de les Planes locality (MCD-5149 and MCD-5150, respectively). (P) Cast from the Orcau-4 locality (MCD-5155). (Q) Hadrosauropodus langstoni cast (TMP 87.76.6) from the St. Mary River valley locality of the USA, after Lockley et al. [54]). (R) Cast (CU-MWC 224.1–224.11) from the Zerbst ranch locality of the USA, after Lockley et al. [54]. (S) Cast (MPD 100F/11) from the Nemegt locality of Mongolia, after Currie et al. [11]. (T) Cast from the Bugin Tsav locality of Mongolia, after Ishigaki et al. [12]. Scale bar: 15 cm. All drawings are in sole view, except A, C, and D which are in top view.
Figure 8.
Hadrosaur trackways in southwestern Europe.
(A, B, and D) Bipedal trackways from the Areny 1, Moror B, and Sierra de los Gavilanes tracksites (redrawn from Barco et al. [19], Llompart [18], and Herrero-Santos, [24], respectively). (C) Quadrupedal trackway from the La Mata del Viudà tracksite.
Figure 9.
Chronostratigraphic correlation of uppermost Cretaceous deposits (Arén Sandstone and Tremp formations) in the southern Pyrenees (SW Europe).
The standard geomagnetic polarity timescale is taken after Ogg and Hinnov [41]. See “Methods” section for further details on section abbreviations and magnetostratigraphical source data.
Figure 10.
Sedimentary reconstruction of hadrosaur track production in fluvial settings of the Tremp Formation.
(A) Sedimentary environments in meandering streams. (B) Sedimentary environments in braided streams.
Figure 11.
Age distribution and hadrosaur track size.
(A) Graph showing the temporal abundance (%) of hadrosaur tracks in geologic formations of North America (NA), Asia (AS), South America (SA), and Europe (EU) through the Campanian, Campanian–Maastrichtian, and Maastrichtian time spans. (B) Size (track length, in cm) distribution of hadrosaur tracks through the abovementioned regions in the Campanian to Maastrichtian time span. Ib-Ar, Ibero-Armorican island. See source data in Dataset S1.