Description and Classification

The footprints named Prestwichianna provide clues about the animals that made them. These tracks often show four or five distinct toe impressions, sometimes with signs of claws. The overall shape can appear somewhat hand-like, which is a characteristic of a broader group of fossil footprints called chirotheriid (meaning “hand-beast”) tracks. Individual prints can vary in size, but they generally indicate fairly large animals walking on their toes (digitigrade). The pattern of the trackways, which are series of footprints, can help scientists estimate how the animal moved and its approximate size.

In terms of classification, Prestwichianna is an ichnotaxon. This means it’s classified based on the features of the trace fossil itself, not on the bones of the animal that made it, because the exact trackmaker is usually unknown. While the specific animal identity remains a mystery, the characteristics of Prestwichianna tracks suggest they were made by an archosaur. Potential candidates include early crocodile-line archosaurs, large rauisuchians (a group of formidable Triassic predators related to crocodiles), or possibly very early dinosauromorphs (animals closely related to the first true dinosaurs). These tracks are important because they show the presence of these large reptiles in Triassic ecosystems.

Distinguishing Features

Prestwichianna footprints can be recognized by several key characteristics:

• Typically display four to five toe impressions, indicating a pentadactyl (five-fingered/toed) or functionally tetradactyl (four-toed) foot.
• The prints often have a “hand-like” (chirotheroid) appearance, with some digits being longer than others.
• Claw impressions may be visible at the tips of the toes.
• The animal walked on its toes, a posture known as digitigrade.
• Trackways may show an inward rotation of the front foot prints (manus) relative to the hind foot prints (pes), if both are preserved.

Paleoenvironment and Diet

The Triassic period, when the animals making Prestwichianna tracks lived, was a time of recovery and diversification of life after a massive extinction event at the end of the preceding Permian period. The environments where these tracks are found were often semi-arid to seasonally wet plains with rivers and lakes. The sediments that preserved the footprints, such as sandstones and mudstones from the New Red Sandstone in England, indicate these kinds of habitats. The presence of large archosaur tracks like Prestwichianna tells us that these environments supported sizable terrestrial animals.

Since the exact animal that made the Prestwichianna tracks is unknown, its diet can only be inferred based on likely trackmakers. Many of the large archosaurs of the Triassic period, such as rauisuchians, were carnivores, preying on other reptiles and early mammal relatives. If Prestwichianna tracks were made by such predators, then their diet would have consisted of the various animals sharing their habitat. The footprints themselves do not directly reveal diet, but they place a large animal in an environment where it would have needed to find food.

Significance and Ongoing Research

Prestwichianna footprints are significant because they provide valuable evidence of archosaur diversity, distribution, and behavior during the Triassic period, especially in regions where skeletal fossils of these animals are scarce. Trace fossils like these help paleontologists understand which types of animals were present in ancient ecosystems and how they moved. They can reveal animal sizes, walking speeds, and even social behavior if multiple trackways are found together.

Ongoing research involving Triassic footprints, including those like Prestwichianna, continues to refine our understanding of this crucial time in vertebrate evolution. Scientists study these tracks by:

• Comparing them with footprints from other parts of the world to understand global faunal patterns.
• Attempting to link specific track types more closely to known skeletal remains of Triassic archosaurs, much like Batrachopus tracks are linked to crocodylomorphs.
• Using advanced imaging techniques to reveal more details in the footprints.
• Analyzing trackways to learn more about locomotion and biomechanics of the trackmakers, shedding light on the early evolution of dinosaurs and their relatives.

As new fossil discoveries are made and analytical methods improve, our interpretation of Prestwichianna and other ichnofossils will continue to evolve, providing deeper insights into the world of the Triassic.