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Three parallel, manus-only sauropod trackways from the Coffee Hollow A-Male tracksite (Glen Rose Formation, Kendall County, Texas) were studied separately by researchers from the Heritage Museum of the Texas Hill Country and the Houston Museum of Natural Sciences. Footprint and trackway measurements generally show good agreement between the two groups' data sets. Footprints appear to be shallowly impressed true tracks rather than undertracks. One of the Coffee Hollow trackways shows marked asymmetry in the lengths of paces that begin with the left as opposed to the right forefoot, and two of the Coffee Hollow trackways are unusually broad. The Coffee Hollow trackways differ enough from the manus portions of other Glen Rose Formation sauropod trackways to suggest that they were made by a different kind of sauropod. Greater differential pressure exerted on the substrate by the forefeet than the hindfeet probably explains the Coffee Hollow trackways, like other manus-only sauropod trackways, but the possibility that they indicate unusual locomotion cannot at present be ruled out. [ABSTRACT FROM AUTHOR]

Diplocraterion, a U-shaped burrow attributed to infaunal invertebrates, is normally a shallow-marine trace fossil and not part of a continental vertebrate ichnoassemblage. Hence, the Glen Rose Formation (Aptian–Albian) of Texas (USA) presents an opportunity to studyDiplocraterionassociated with a world-class dinosaur tracksite. MostDiplocraterionare in a bioclastic wackestone–packstone bed just above the Taylor Tracklayer, a significant dinosaur track horizon.Diplocraterionare consistently sized, but with variable depths; most have protrusive spreiten and northeast–southwest trends. SmallerArenicolitesco-occur withDiplocraterion, and other trace fossils includeRhizocoralliumand a large theropod trackway. Based on our analysis, a sea-level rise buried the Taylor Tracklayer, with a shallow-marine carbonate mud colonised byDiplocraterionandArenicolitestracemakers. ProtrusiveDiplocraterion, eroded burrow tops,Rhizocorallium, and other criteria point towards firming and net erosion of the bed caused by a stillstand. The depositional environment of theDiplocraterionbed was possibly a subtidal lagoon that covered shoreward sediments impacted by large theropods. Burrow orientations suggest bidirectional currents consistent with trends of theropod trackways, implying each were controlled by a shoreline. The results of our study demonstrate how marine invertebrate and continental vertebrate trace fossils can be used together to define fine-scale changes in former carbonate shorelines. [ABSTRACT FROM AUTHOR]