Exploring the Spatial Intelligence of Ancient Tracemakers, Some Preliminary Thoughts

Animal locomotion and burrowing behaviors are quintessential manifestation of embodied intelligence and spatial intelligence. Embodied intelligence represents the extension and deepening of artificial intelligence into the physical world. Its core premise is that intelligence does not originate from mere abstract computation but is generated through dynamic interactions between an organism’s body, space, and environment. The large-scale emergence of metazoan burrowing around the Ediacaran–Cambrian transition marks a critical milestone in the evolution of behavioral complexity. A representative ichnological signature of this period is the appearance of trace fossils with regularly branching, circular, and regularly sinuous morphologies, which embodies the “Cambrian Information Revolution” and a significant elevation in animal spatial intelligence. Based on systematic investigations of deep-sea trace fossils from the Middle–Upper Ordovician in western Inner Mongolia, we identified multiple trace fossil types with high regularity and complex geometric forms. These findings demonstrate distinct behavioral complication and novelty in deep-sea communities during the Middle–Late Ordovician, providing important behavioral evidence for organism–environment co-evolution during the Ordovician Radiation. Systematic quantitative morphological characterization and function-morphological analysis of a specific circular-branching trace fossil reveal an area-restricted successive probing feeding pattern that probably arose as a modification of the irregular linear searching patterns common in Cambrian shallow-marine treptichnids. Neurologically, this trace morphology is consistent with regularly modulated locomotor Central Pattern Generators (CPGs). According to the topological classification scheme, trace fossils are divided into three categories: line-form, tree-form, and net-form, with the latter two collectively referred to as branching trace fossils. As direct archives of deep-time biological behavior, branching trace fossils (e.g., burrows such as Chondrites, Thalassinoides, Paleodictyon, and Dendrorhaphe, and borings like Abeliella) exhibit pronounced self-similarity and fractal characteristics in their morphology. Similarly, graphoglyptid traces with regularly repeating geometric patterns likely reflect the self-organizing behaviors of ancient animal communities, making branching trace fossils essential for studying biological fractals and self-organization in behavior. Trace fossils form through dynamic interactions between organisms and sediment particles in a physical space; biogenic burrows, in particular, are direct outputs of an animal’s “perception–decision–action” process. Thus, the fractal morphology of branching trace fossils represents a classic example of bio-physical coupled fractals and behavioral self-organization, which may provide bio-inspiration for the development of spatial intelligence in terms of perception, cognition, decision-making, and behavioral coordination, highlighting the need for further systematic investigation.