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preliminaryscientificfindings—thattheLowerCretaceousBroomeFormationheld
a huge number and variety of dinosaur tracks—Thulborn showed photographs of
what were then known as the largest extant footprints made by any land animal in
thehistoryoftheearth.Someofthesauropodtrackswerenearlytwometersacross;
I'd slept in beds smaller than these tracks. At the end of his presentation, he an-
nounced with rightful pride, “Mine's the biggest!” (Just for context, he was talking
about the tracks.)
AdditionalphotosshownbyThulborneffectivelycommunicatedanotherpoint
he wanted to make, which was that the dinosaurs—which were mostly sauropods,
but also included some large theropods—had literally impacted their environments.
Through sheer quantity of footfalls, as well as those footfalls coming from massive
animals, the sauropods—and to a lesser degree the theropods—had altered the sur-
faces of their landscape enough to change the topography of their local envir-
onments. In 2012, Thulborn elaborated on that idea in an article titled “Impact
of Sauropod Dinosaurs on Lagoonal Substrates in the Broome Sandstone (Lower
Cretaceous), Western Australia.” In that paper, he provided evidence that the di-
nosaurs had stomped soft sediments along a lagoonal shoreline so much that they
formed low-lying areas flanked by higher areas, like levees on either side of well-
worn trails.
Furthermore, these trails may have been routes used habitually by the dino-
saurs. Once established, they became paths of least resistance for moving about, as
if they made their own highways. Photographs in Thulborn's article showed huge
sauropod tracks in depressed areas, but no tracks on the elevated areas on either
side. The sandstones also lack plant-root trace fossils or other evidence of fossil
plants, so it either was an already clear area for the dinosaurs to saunter through
there or they denuded it by stomping plants into submission, while also compacting
the soils, which prevented further plant colonization.
So imagine an Early Cretaceous shore next to a lagoon, with these deeply im-
pressed trails running parallel to the average high-tide mark along that shore. With
