Scientists have described a trackway of a theropod dinosaur beautifully preserved in soft mud, now turned to stone, within Lower Jurassic strata at St George in south-western Utah, USA (figure 1).1 As well as leaving a trail of footprints, they report the dinosaur left intermittent tail drags, and in one placesat in the mud and left impressions of both of its hands, its feet, its tail, and its buttocks.2 The tracks were found in the Whitmore Point Member of the Moenave Formation at the Dinosaur Discovery Site at Johnson Farm, St George.

The report focused on connecting the dinosaur traces with the anatomy, posture and behaviour of birds, citing as evidence the rotation of the dinosaur’s forearm and the way it sat in the mud. However, in their preoccupation with the unsubstantiated speculation of birds evolving from dinosaurs the authors overlooked the obvious evidence of huge watery catastrophe recorded by the fossils and the rocks.

The Whitmore Point Member is a 20-m-thick deposit of mudstone, shale and sandstone strata, and has abundant horizons containing dinosaur trackways (figure 2), including tracks of theropods that were larger and smaller than the ones described in the report.3 The strata also contain clawmark tracks, indicating times when the animals were swimming in deep water and just managing to scratch their claws along the sand on the bottom.4 The sediment beds are also packed with body fossils including megaplants, sharks, lungfish, coelacanths, ray-finned fish, crustaceans, clams and dinosaur remains. To preserve such an abundance of body fossils and footprints requires rapid sedimentation in order to prevent the degradation processes that would normally destroy them….

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