# An updated classification of animal behaviour preserved in substrates

> Fossil footprints, burrows, droppings and bite marks are the only way to watch ancient animals move, feed, hunt and raise young. Three ichnologists review more than 60 years of ways to sort these traces by behaviour, borrow classic questions from animal behaviour science, and offer an updated scheme of 13 behaviour types, from resting and dwelling to moulting and digestion. Many of their questions apply just as well to fresh tracks and signs.

Summary by Kersey Lawrence, Original Wisdom. Updated 9 November 2026. Page: https://www.originalwisdom.com/tracking-literature/2016-vallon-rindsberg-updated-classification-animal-behaviour/

## Citation and access

- **Authors:** Lothar Herbert Vallon, Andrew Kinney Rindsberg and Richard Granville Bromley
- **Year published:** 2016
- **Journal or source:** Geodinamica Acta
- **Full citation:** Vallon, L. H., Rindsberg, A. K. and Bromley, R. G. 2016. An updated classification of animal behaviour preserved in substrates. Geodinamica Acta 28(1–2): 5–20.
- **DOI:** 10.1080/09853111.2015.1065306
- **Access status:** Hosted (freely available elsewhere)
- **PDF:** https://www.originalwisdom.com/wp-content/uploads/2026/11/2016_Vallon_and_Rindsberg_etal_an-updated-classification-of-animal-behaviour-preserved-in-substrates.pdf

## Tags

- **Tracking:** Burrows; Feeding signs; Scat; Tracking; Tracks; Tracks and signs identification
- **Behaviour and ecology:** Behaviour; Feeding; Movement; Nesting; Predation; Scavenging
- **Methods and technology:** Literature review
- **Data type:** Review
- **Observer qualification:** Not needed
- **Discipline:** Behaviour and ecology; Ichnology
- **Year published:** 2016

## Detailed keywords

- **Species:** No species studied directly; the paper is about trace fossils (fossil tracks, trails, burrows, borings, nests, droppings and other traces) and the behaviour of the animals that made them, mostly invertebrates. Examples discussed: worms and polychaetes, bivalves (including Lucinidae, Thyasiridae and Solemyidae), limpets, sea urchins, sea stars (asterozoans), trilobites, decapod crustaceans, callianassid shrimps, innkeeper worm (Urechis caupo), fiddler crab (Uca pugnax and Uca spp.), ghost crab (Ocypode quadrata), insects (beetle larvae, Scolytinae bark beetles, leafcutter ants (Atta colombica), termites, mud-dauber wasps, caddisfly larvae), spiders, earthworms, amphibians, lungfish, fish, reptiles, birds (hawks and owls), the dinosaur Troodon, herbivorous mammals, deer and frogs. Many trace fossil names (ichnogenera) are given, for example Cruziana, Rusophycus, Skolithos, Thalassinoides, Chirotherium (a vertebrate trackway) and Oichnus (drill holes in shells).
- **Location and habitat:** Not a field study. Examples come from deep-sea, shallow marine, tidal, freshwater and land settings, including fossil soils (palaeosols) and the Solnhofen Lithographic Limestones (Upper Jurassic, southern Germany). The authors are based in Denmark and the United States.
- **Topics:** ichnology (the study of traces); trace fossils; ethological (behavioural) categories of traces; Seilacher’s 1953 classification and Bromley’s 1996 scheme; Tinbergen’s four questions applied to traces, plus a fifth question on how the trace was made; palaeoecology and the ichnofacies concept; neoichnology (modern traces); resting, dwelling, feeding, grazing, farming, locomotion, escape, predation (including scavenging), brooding and nesting, attachment, chemosymbiotic, digestion (coprolites, regurgitated pellets, gastroliths) and moulting traces; transitions between behaviours within one trace; categories not recommended (aedificichnia, equilibrichnia, impedichnia, mortichnia, polychresichnia). Minor slips in the paper: “Equilibrichna” for equilibrichnia in section 4, and “Miller, 2003, 2003” in section 5. Table 1 notes that accepted terms are in bold.
- **Statistics or models:** None
- **Data type:** Review of the published literature and of proposed categories, with an updated classification scheme. Some personal observations by the first author are mentioned. Published online 16 July 2015; in the 2016 print volume.

## Synopsis

### 1. What they did

Fossil tracks, trails, burrows, borings and droppings are the only direct signs of how ancient animals moved, fed, hunted and lived. Since 1953, scientists who study these traces (ichnologists) have sorted them by the behaviour that made them, starting with five groups proposed by Seilacher: resting, dwelling, combined dwelling and feeding, locomotion, and grazing traces. Bromley (one of the authors) updated the scheme in 1996, but many more categories have been proposed since.

The authors:

- Reviewed every proposed category. They listed 34 behavioural categories proposed since 1953 and measured how often each is used by counting Google Scholar citations (Table 1).

- Brought in ideas from animal behaviour science. They adapted Tinbergen’s four classic questions about behaviour (its function, what controls it, how it develops during an animal’s life, and how it evolved) for fossil traces, and added a fifth: how was the trace made?

- Recommended how to use each category. Where a category described a rare or very specialised behaviour, they folded it into a broader category as a subcategory, to keep the total number small.

- Drew an updated diagram of the scheme, based on Bromley’s, with arrows showing how one behaviour can turn into another within a trace (Figure 1).

### 2. What they found

Thirteen categories recommended

- Farming traces (agrichnia): highly regular, patterned burrows, mainly in the deep sea, possibly used to grow microbes for food.

- Brooding traces (calichnia): structures built by adults to raise young, from insect brood chambers to vertebrate nests, including pits, mounds and birds’ nests.

- Chemosymbiotic traces (chemichnia): burrows of animals living with bacteria that need chemicals from deeper, oxygen-poor sediment.

- Resting traces (cubichnia): shallow hollows from short stays, such as resting, hiding or hibernating. These often show the outline and underside of the animal, so they give the best chance of identifying who made them. Landing and take-off traces of flying or leaping animals are included here.

- Digestion traces (digestichnia): droppings (coprolites), regurgitated pellets, gut contents and stomach stones (gastroliths). The authors note that some bird pellets, such as those of hawks and owls, have a recognisable shape. Because animals digest and excrete during almost any activity, this category links to all others.

- Dwelling traces (domichnia): permanent or semi-permanent burrows and borings, including aestivation chambers (aestivichnia), where earthworms, amphibians and lungfish wait out bad conditions.

- Moulting traces (ecdysichnia): traces left while moulting or shedding, including insect pupation chambers (pupichnia). The authors give the example of a deer rubbing newly grown antlers on a tree and scratching the bark.

- Attachment traces (fixichnia): marks on hard surfaces where an animal anchors itself for life.

- Feeding traces (fodinichnia): burrows of animals eating their way through sediment, including wood borings (xylichnia) and insect larval mines in leaves, bark and wood.

- Escape traces (fugichnia): made by animals digging up after sudden burial. Failed escapes (taphichnia) are included, because the behaviour is the same whether or not the animal survives.

- Grazing traces (pascichnia): meandering or spiral trails of animals feeding as they move.

- Predation traces (praedichnia): drill holes and chipped shells, and gnawing and biting marks on bones (mordichnia). Scavenging is included here, because it is often impossible to tell whether bone marks were made during an attack or long after death. Trapping traces (irretichnia), such as pitfalls and spider webs, are a subcategory.

- Locomotion traces (repichnia): all traces of moving, including trails, trackways of footprints (cursichnia), swimming traces (natichnia, navichnia) and wing marks of animals flying just above the ground.

Categories not recommended

- Above-ground structures (aedificichnia) and multipurpose social insect nests (polychresichnia), because they serve several purposes and fit better under their main one.

- Equilibration traces (equilibrichnia), where animals shift their burrows as sediment builds up or erodes. The underlying behaviour is dwelling or feeding, so the authors prefer “equilibrated dwelling” or “equilibrated feeding” traces.

- “Death struggle” traces (mortichnia), because they cannot be recognised without the body at the end, and many supposed examples from Solnhofen end in shed skins (exuviae) rather than corpses.

- Embedment structures in a host (impedichnia) and plant galls (cecidoichnia), which are not traces made by moving substrate; the authors suggest the neutral names impeditaxa and cecidotaxa.

Mixed behaviours are the rule

Most animals do more than one thing in their lives, and many traces record several behaviours at once, for example a grazing trail that includes resting hollows, or termite nests used for dwelling, farming and raising young. For practical reasons, each trace type is usually listed under its most distinctive behaviour.

### 3. What they concluded

- To keep the number of categories small, some newer categories are best treated as subcategories of well-established ones that reflect a broader behaviour.

- The updated diagram shares the strengths of Bromley’s 1996 version, showing transitions between behaviours to help classify and interpret traces.

- After more than 60 years, Seilacher’s behavioural classification is still the framework palaeoichnologists work in, and it remains useful for thinking about traces, although not everything needs to be categorised.

- What is needed is a clearer connection between ideas from biology (such as Tinbergen’s) and ideas from palaeontology (such as Seilacher’s).

### 4. How tracking was or was not used

No tracking fieldwork was done. The paper is about how to read animal behaviour from traces left in sand, mud, soil, wood, shell and rock, mainly fossil traces. It draws on modern traces for comparison, for example fiddler and ghost crab burrows, bird pellets (citing Elbroch and Marks 2001) and a deer’s antler rubs on a tree.

### 6. Other technologies, skills or innovations

- A fifth question added to Tinbergen’s four for anyone interpreting a trace: how was it made? This covers the overall shape, clues to how it was dug, marks left by the maker’s body (bioprint) and claws or other appendages (bioglyphs), and whether a burrow wall is lined.

- A worked example of applying all five questions to a fossil nest of the dinosaur Troodon.

- Google Scholar citation counts as a simple measure of which proposed terms scientists actually use.

### 8. Implications for tracking (Original Wisdom's observations)

_These are Original Wisdom's observations, not the authors'._

- The authors’ five questions (what was the animal trying to do, what in its surroundings shaped the behaviour, how does the trace change as the animal grows, how did the behaviour evolve, and how was the trace made) are a useful checklist for any tracker interpreting tracks and signs, not only fossil ones.

- The point that one trail or sign often records a change of behaviour (moving, then resting, feeding, or being caught by a predator) matches how trackers read a trail as a sequence of activities.

- The difficulty of telling predation from scavenging by bone marks alone is familiar from kill site and carcass work in modern tracking.

## Cite this summary

Lawrence, K. 2026. Summary of: An updated classification of animal behaviour preserved in substrates (Vallon and Rindsberg et al., 2016). Original Wisdom, Tracking Literature. https://www.originalwisdom.com/tracking-literature/2016-vallon-rindsberg-updated-classification-animal-behaviour/