in the same 290-million-year-old strata. They matched the two most common trackways with the two most common fossils, two reptile-like herbivores known as Diadectes absitus (with the trackway pseudonym Ichniotherium cottae) and Orobates pabsti (with the trackway pseudonym of Orobates pabsti). The Permo-Carboniferous of Prince Edward Island, Canada contains trackways of tetrapods and stem-reptiles. Macrofloral and palynological information help date them. Ireland hosts late Middle Devonian tetrapod trackways at three sites on Valentia Island within the Valentia Slate Formation. The earliest fossil trackway of primitive tetrapods in Australia occurs in the Genoa River Gorge, Victoria, dating from the Devonian 350 million years ago. Dinosaur trackways Dinosaurs lived on the continents before grasses evolved (the "Age of the Grasses" evolved with the "Age of the Mammals"); the dinosaurs lived in the Triassic, Jurassic, and Cretaceous and left many trackways, both from plant-eaters and the meat-eaters, in various layers of mud and sand. With scientific analysis, dinosaur specialists are now analyzing tracks for the walking-speeds, or sprint-running speeds for all categories of dinosaurs, even to the large plant eaters, but especially the faster 3-toed meat hunters. Evidence of herding, as well as pack hunting are also being investigated. Brazil Valley of the Dinosaurs, Paraíba, Brazil Africa Namibia In north-central Namibia there is a dinosaur trackway in sandstone on what is now the private farm Otjihaenamparero. Larger footprints are of a ceratosauria and smaller ones of syntarsus. The prints are believed to be around 190 million years old. Zimbabwe In the Lower Zimbabwe Rift Valley there is a trackway in 140 Ma rose-coloured sandstone of Chewore Area. The small footprint size, with both manus and pes, implies that it is a trackway of a juvenile, a probable carnosaur. North America The western regions of North America, especially the western border of the Western Interior Seaway, are common for dinosaur trackways. Wyoming has dinosaur trackways from the Late Cretaceous, 65 ma. (A model example of this 3-toed Wyoming trackway was made for presentation) In the United States, dinosaur footprints and trackways are found in the Glen Rose Formation, the most famous of these being the Paluxy River site in Dinosaur Valley State Park. These were the first sauropoda footprints scientifically documented, and were designated a US National Natural Landmark in 1969. Some are as large as about 3 feet across. The prints are thought to have been preserved originally in a tidal flat or