Fossil trackway

Laetoli Site, February 2006

Some of the earliest trackways for human ancestors have been discovered in Tanzania. The Laetoli trackway is famous for the hominin footprints preserved in volcanic ash. After the footprints were made in powdery ash, soft rain cemented the ash layer to tuff, preserving the prints. The hominid prints were produced by three individuals, one walking in the footprints of the other, making the original tracks difficult to discover. As the tracks lead in the same direction, they might have been produced by a group — but there is nothing else to support the common reconstruction of a nuclear family visiting the waterhole together.

In South Africa, two ancient trackways have been found containing footprints, one at Langebaan and one at Nahoon. Both trackways occur in calcareous eolianites or hardened sand dunes. At Nahoon, trackways of at least five species of vertebrates, including three hominid footprints, are preserved as casts.[2] The prints at Langebaan are the oldest human footprints, dated to approximately 117,000 years old.[3]

Twenty six human fossil trackways have been found in the Willandra Lakes area adjacent to Lake Garnpung, consisting of 563 human footprints from 19,000 to 20,000 years ago.[4]

• Valley of the Dinosaurs, Paraíba, Brazil

An example trackway from Africa is a trackway in 140 Ma rose-coloured sandstone of Chewore Area, Lower Zimbabwe Rift Valley.[10] The small footprint size, with both manus and pes implies that it is a trackway of a juvenile, a probable carnosaur.

Probable Dilophosaurus footprint from Red Fleet State Park, northeastern Utah.

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.[11] (A model example of this 3-toed Wyoming trackway was made for presentation.)[12]

Theropod and sauropod tracks under water in the Paluxy River

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 a lagoon.[13] There are tracks from two types of dinosaur. The first type of tracks are from a sauropoda and were made by an animal of 30 to 50 feet in length, perhaps a brachiosaurid such as Pleurocoelus,[13] and the second tracks by a theropoda, an animal of 20 to 30 feet in length, perhaps an Acrocanthosaurus. A variety of scenarios was proposed to explain the tracks, but most likely represent twelve sauropods "probably as a herd, followed somewhat later by three theropods that may or may not have been stalking -- but that certainly were not attacking." [13]

• Dinosaur tracks, near Moab, Utah[14]
• Dinosaur Footprints Reservation in Holyoke, Massachusetts, USA
• Red Gulch Dinosaur Tracksite, Wyoming
• Prehistoric Trackways National Monument near Las Cruces, New Mexico
• Connecticut River Valley trackways, in New England
• Clayton Lake State Park dinosaur trackway near Clayton, New Mexico

The Gansu dinosaur trackway located in the Liujiazia National Dinosaur Geopark in Yanguoxia, China contains hundreds of tracks including 245 dinosaur, 350 theropod, 364 sauropod and 628 ornithopod tracks among others.[15]

• Mammoth, White Sands National Park. Near Alamogordo, New Mexico

A recent marsupial trackway site in the Colac district of Australia (west of Colac) contains marsupial trackways as well as kangaroo and wallaby tracks.[16]