The Earth Remembers Their Steps
At the edge of a Cretaceous floodplain, where tall ferns met the muddy banks of the river and time seemed to hold its breath, a young researcher, who may have been named Leia, stumbled upon something unusual. In the stone bathed in morning light, she discovered deep fossilized tracks left by the mighty feet of a stegosaurus. Each imprint, like a silent message, revealed the life of these majestic creatures: grazing on prehistoric plains and wandering beneath towering trees. The air hung heavy with the scent of plants and damp earth, while distant sounds seemed like calls from invisible beings.
Filled with curiosity, Leia envisioned stegosauruses adorned with spikes and massive plates on their backs peacefully strolling across this ancient land. These tracks were not mere relics of a fleeting moment; they were a portal to long-gone lives, rich with mysteries and untold stories. For Leia, the ancient trail became the beginning of a new adventure, recorded not in words but in stone.
Now, let us follow these ancient dinosaur tracks, taking our own journey into their unusual world, to uncover the stories they’ve preserved and learn more about what they reveal about the past.
Footprints through Time
Dinosaur tracks are quite numerous in many areas of the world, creating a captivating glimpse into a time long gone. For instance, these fossilized footprints occur in diverse locations, from rocky outcrops to muddy riverbeds, revealing the widespread existence of dinosaurs across different environments. By studying dinosaur trackways, researchers can gather valuable scientific insights into their behavior, including movement, social interactions, and how they navigated the world around them.
Major Types of Dinosaur Tracks
As a rule, it is often difficult or impossible to identify the particular genus or species of dinosaur that made a given trackway. However, one can usually determine at least the general group of dinosaurs to which the trackmaker belonged, since foot structures vary considerably among different dinosaur groups. Furthermore, in many cases, the locomotor styles of different groups varied as well. The footprints indicate whether a bipedal or quadrupedal dinosaur made them, as both types existed among the Ornithischians and Saurischians.1
Bipedal dinosaur tracks are the most common. They contain left-right sequences of similarly shaped prints, each containing three major digit marks. People commonly refer to them as “three-toed tracks” or “tridactyl tracks.” Most bipedal dinosaurs actually possessed four digits on each foot, but one digit (the hallux) was small and held in an elevated position at the inside rear of the foot. Consequently, when recorded at all, hallux marks are typically small and shallow. Bipedal dinosaurs, mainly theropods and some groups of ornithischians, primarily left tridactyl footprints.
A well-preserved theropod dinosaur track usually has claw marks at the tips of the toes. The toes appear rather slender, and the footprint is longer than it is wide, which gives it a characteristic “V shape.”
In contrast, a well-preserved track of a large herbivorous ornithopod often lacks distinct claw marks. The tips of the toes are blunter and more rounded. The wider toes and shorter foot length give the track a “U shape.”
These distinctive footprints have been cataloged and studied extensively, leading to the classification of numerous ichnogenera—formally named types of fossil footprints attributed to dinosaurs. The List of Dinosaur Ichnogenera compiles these classifications and represents the most comprehensive record of known dinosaur tracks (excluding those of birds, class Aves). However, it also includes some invalid genera, dubious names (nomen dubium), formally undescribed names (nomen nudum), various junior synonyms, as well as ichnogenera that no longer pertain to dinosaurs.
Theropods
Theropod tracks typically exhibit relatively long and narrow digit impressions, terminated with sharp, slender claw marks. Furthermore, the posterior ends are typically somewhat V-shaped. Coelurosaur tracks often exhibit digits held closely together and distinct toe pads. The shapes and positions of the pads are useful in identifying particular ichnogenera. The digit marks of carnosaur tracks are frequently more widely splayed and robust, with less distinct pads.
Theropod foot morphology appears in the ichnological record from the Middle Triassic, slightly predating the earliest body fossils. Initially, early theropods like Herrerasaurus had foot structures producing both tridactyl and tetradactyl tracks.
By the Late Triassic–Early Jurassic, most theropod tracks belonged to a single ichnotaxon, Grallator–Eubrontes, associated with ceratosaurs, basal tetanurans, and carnosaurs. These track types persisted into the Jurassic and Cretaceous, indicating stable foot morphology across different theropod clades. Theropod footprints resemble those of small and medium-sized ornithischians, complicating identification. This similarity may stem from convergent evolution due to shared locomotion styles.
Deinonychosaurian theropods, the sister group to birds, had a large raptorial claw located on a highly modified second toe, which was held in a retracted position while moving—a feature reflected in the tracks they left behind. These closely spaced, parallel tracks—identified as belonging to the ichnogenera Velociraptorichnus and Dromaeosauripus—offer evidence of pack behavior among deinonychosaurian theropods in the Early Cretaceous period in Shandong Province, China.
Coelurosauria, a large subgroup of theropods, includes important taxa such as compsognathids, tyrannosauroids, ornithomimosaurs, maniraptorans, and megaraptorans (which contain birds). These were very large dinosaurs (like Tyrannosaurus) as well as quite small ones (like Parvicursor), consisting of insectivorous, herbivorous, and carnivorous species. Coelurosaurian fossil remains and tracks date back to the late Triassic to early Jurassic. An example includes Neotripodiscus from South Africa (Lesotho) and the late Cretaceous Magnoavipes.
Some of the Theropod Tracks
Grallator is an ichnogenus representing small (5–20 cm) three-toed footprints, typically left by various small, bipedal, predatory theropod dinosaurs. These tracks have a very similar shape, making it difficult to distinguish them from one another, since the type of sediment in which they formed greatly influences the details.
The phalangeal formula for Grallator tracks is ?-3-4-5-?, with the third toe being the longest. Toes II and IV are unequal in length, and the outer toes have reduced enough that they usually don’t leave an impression on the ground. However, the hallux (first toe) rarely impressed. Fossilized tracks often preserve the phalangeal pads well.
Grallator footprints are mesaxonic (centered on the third toe), with the foot being wider than it is long. The angle between the preserved toes (digit divarication) typically ranges from 18° to 37°.
Researchers have discovered these tracks worldwide, ranging from the Early Triassic to the Early Cretaceous, in regions such as North America, Greenland, Europe, India, Australia, Brazil, and China. In particular, they are especially abundant in the northern part of the Newark Supergroup along the eastern coast of North America, dating to the Triassic and Early Jurassic periods.
Many Grallator tracks are thought to have been made by primitive dinosaurs similar to Coelophysis or Caudipteryx. Edward B. Hitchcock first described the ichnogenus in 1858 in the United States. Over time, researchers have assigned different names to various similar tracks, and some of the most common synonyms include Hunanpus, Coelurosaurichnus, Dilophosauripus, Megalosauropus, and Kayentapus.
Eubrontes. This is a larger variation of the three-toed track of a predatory theropod. Eubrontes (25–50 cm) surpasses Grallator in size and dates to a narrower time range, specifically from the Late Triassic to the Early Jurassic. Bipedal dinosaurs such as Dilophosaurus, Podokesaurus, and Sinosaurus apparently left these tracks. Their distribution is as broad as that of Grallator, but they also occur in Africa (Lesotho, Morocco). Synonym: Anchisauripus.
Velociraptorichnus. This ichnogenus refers to dinosaur tracks that scientists attribute to a small dromaeosaurid, likely related to Bambiraptor. One well-preserved footprint, measuring about 10 cm in length, suggests the trackmaker was around 1.2 to 1.6 meters long and weighed approximately 4 to 5.6 kilograms.
Like other dromaeosaurids, the second toe had a sickle-shaped claw that the animal retracted while walking. Only the base (proximal part) of digit II contacted the ground during movement. The tracks feature straight, narrow digits.
Fossils of Velociraptorichnus occur in Early Cretaceous (Barremian–Aptian) deposits across eastern Asia and western North America, particularly in Utah.
Dromaeopodus refers to narrow, two-toed (didactyl) tracks left by a bipedal dinosaur. In these footprints, digit III is just slightly longer than digit IV, and digit II shows a short, rounded impression. The tracks of digits III and IV are nearly parallel, showing sharp claw marks, and both toes curve slightly inward.
Apparently, the animal retracted the claw while walking, as evidenced by a small, rounded mark of digit II. This trait is characteristic of dromaeosaurids. In addition, the nearly equal lengths of digits III and IV, their almost parallel alignment, and the prominent, rounded pad impression at the base of digit II all indicate a specialized foot structure. This pad likely cushioned the joint, especially in larger individuals.
One of the standout features of Dromaeopodus tracks is the presence of a large heel pad beneath the metatarsal-digital joints. Although heavy, slow-moving (graviportal) dinosaurs like sauropods often show heel pads in their tracks, non-avian theropod footprints rarely display them.
The foot length ranges from 26 to 28.5 cm, indicating the trackmaker was likely a large dromaeosaurid. Fossils of Dromaeopodus occur in Early Cretaceous (Barremian–Aptian) rocks across eastern Asia and western North America.
Magnoavipes. Tracks are large, slender, three-toed footprints with long, thin toes that do not spread as wide as those in birds. The footprint is very large and as long as it is wide. The heels were small, and the toe pads were only slightly distinct. Sharp claw impressions are visible on all three digits.
The arrangement of the tracks suggests a zigzagging gait, and the proportions point to an animal with very long legs similar to those of modern wading birds. Obviously, the tracks almost certainly belong to a non-avian coelurosaur, most likely an ornithomimid, a group of fast, ostrich-like theropods.
Fossils of Magnoavipes have been found in Late Cretaceous deposits in China’s Shaanxi Province, as well as in Colorado, Texas, and Alaska in North America.
Tyrannosauripus is an ichnogenus characterized by large, slightly asymmetrical, four-toed tracks. The slender hallux (digit I) impression is sometimes visible, though not always present. The tracks typically measure between 85 and 96 cm in length and 55 to 64 cm wide at the level of the posterior ends of the digit impressions. Occasionally there are also handprints.
A large tyrannosaurid, most likely Tyrannosaurus rex, left these tracks. Researchers have documented Tyrannosauripus tracks at several Late Cretaceous sites throughout North America and possibly in Jiangxi Province, China.
A track from Queensland, Australia, once referred to as Tyrannosauripus, no longer fits into the category of Tyrannosaurus or even a theropod. Instead, these tracks were likely left by an ornithopod, probably Muttaburrasaurus.
Ornithopods
In general, ornithopod tracks are wider than those of theropods, with rounded heels and short, blunt toe marks—features that reflect their hoof-like claws. However, the distinction isn’t always clear, especially with small or poorly preserved tracks. Even expert paleontologists debate whether certain tracks belong to small theropods or ornithopods and whether distinct species or juveniles of larger ones created them. Ornithopods, such as Dryosauridae or basal ankylopollexians, left three-toed footprints with fewer toe pads, while Wintonopus prints were smaller with broader digits.
Larger ornithopod footprints are easier to identify, typically displaying three broad toes with thick pad impressions and blunt claws. The well-preserved track of a large ornithopod, a plant-eater, may lack distinctive claw marks. Some preserve manus tracks. Moreover, mud can make things even trickier. When the digits of a carnosaur (a large theropod) sink into soft ground and collapse slightly, their footprints can resemble those of an ornithopod, making them appear shorter and rounder than they actually were. Both groups of dinosaurs normally walked on their toes (a stance called digitigrade), but recent research has shown that some bipedal dinosaurs occasionally walked with their heels touching the ground—like modern bears—creating unexpectedly elongated tracks.
Some Dinosaur Tracks of Ornithopods
Caririchnium. This ichnogenus belongs to the three-toed footprints of ornithopod dinosaurs. Sometimes, small, oval, or rectangular handprints appear alongside these footprints, indicating facultative quadrupedal locomotion. The toes are short and wide, with their distal ends being blunt or somewhat pointed in some species. The heel prints are large and rounded.
Specifically, the creators of such tracks were medium- to large styracosternans, related to basal hadrosaurs or derived iguanodonts. They originate from the Early Cretaceous in China, Brazil, Canada, Switzerland, and Spain, as well as from the Late Cretaceous in the United States.
Similar to theropods, ornithopods made three-toed tracks. The first toe, if present, was higher up the rear of the foot, so it rarely leaves an impression in a track. The toe prints often lack the impressions of individual digital pads. Claw impressions are also usually absent.
Wintonopus. These tracks belong to small, herbivorous, bipedal ornithopod dinosaurs. The footprints range in length from 11 to 44 cm with a width greater than their length. The pes is mesaxonic and tridactyl (digits II-IV) with thick and short toes ending in rounded or blunt tips.
Notably, there are no impressions of phalangeal pads or heel marks. All dinosaurs walk with elevated heels, and their ankle joints functionally behave like part of the lower leg. In most dinosaurs, the rear of the foot that touches the ground is the joint between the toes and the mid-foot (the metatarsal). Most tracks made by bipedal dinosaurs suggest that a pad exists beneath this part of the foot, creating the illusion of a true heel. However, Wintonopus lacks evidence of this false heel pad; it only shows impressions of the toes. This indicates that the ornithopods that left these tracks walked on their toes without any part of the mid-foot touching the ground. This posture is known as “subunguligrade.”
The trackways are narrow, with a pace angulation of about 160 degrees. The trackmaker is presumably a hypsilophodontid dinosaur. Fossils occur in Central West Queensland and the Dampier Peninsula of Australia, dating from the Early Cretaceous (Berriasian to Albian stages) and the earliest part of the Late Cretaceous (Cenomanian stage).
Amblydactylus represents a three-toed footprint attributed to a large, bipedal, herbivorous dinosaur. The tracks are notably broad, with their width equal to or even exceeding their length. Individual footprints typically measure 54–56 cm long, with the largest reaching up to 64 cm. The trackway is narrow and elongated. Furthermore, the individual tracks show a relatively small angle of divarication between toes II and IV when measured against the foot’s central axis. Interdigital webbing connects the proximal parts of the toes, the toes themselves ending in blunt claws.
The forelimb impressions (manus) are crescent-shaped and lack clear indications of individual digits. Based on the stride and spacing, the estimated walking speed of the trackmaker ranges from 3.0 to 8.2 km/h. Some of these tracks originated from sediment deposited under several meters of water, suggesting subaqueous locomotion.
The trackmaker is an ornithopod dinosaur. Sternberg proposed that the Amblydactylus tracks resembled an Iguanodon-like dinosaur because the type specimens show sharper hoof impressions than would typically be expected for hadrosaurs. Additional trackway evidence also shows these animals exhibited gregarious, or social, behavior. Fossils have been found in Early Cretaceous (Aptian) deposits of Canada and mid-Cretaceous (late Albian–Cenomanian) formations in Queensland, Australia.
The Giants: Sauropod Tracks
Among the rare four-legged dinosaur tracks, those made by the massive, long-necked sauropods are the most famous—and the most impressive. Some of their footprints measure over a meter long. Until recently, paleontologists considered sauropod tracks rare, but now they have uncovered dozens of sites worldwide, offering new insights into these prehistoric giants.
Sauropods had five toes on their hind feet, decreasing in size from the inside towards the outside of the foot. The inner three or four often sported large claws that angled outward. Some tracks show well-preserved claws, even though illustrations and skeletal mounts typically misrepresent them. Interestingly, the shape of sauropod footprints varies—some look bear-like, while others appear more triangular, possibly due to differences in age or sex. Their front feet, on the other hand, left tracks similar to those of elephants. Fossilized impressions show five blunt, peg like toes, with one often embedded in a fleshy pad at the front. However, the large claw found in sauropod skeletons is mysteriously absent from most tracks.
Some scientists believe they held it aloft, while others think they tucked it into the footpad, which reduces the likelihood of leaving an imprint. Sauropod tracks exhibit significant diversity, evolving from the Middle Jurassic to the Late Cretaceous. Their forelimb impressions changed from speech-bubble shapes to kidney-like or horseshoe-shaped forms, sometimes preserving a thumb claw (pollex). Hind limb prints were typically subtriangular, with three or four claw marks oriented either forward or slightly outward.
A Few Examples of Sauropod Tracks
Brontopodus refers to the footprints of sauropod dinosaurs. The ichnogenus has a wide-gauge trackway, with tracks spaced far apart that indicate a broad stance. This trackway pattern suggests that the trackmakers were most likely titanosaurs.
The overall shape of the footprints is subtriangular, with four toes, reminiscent of diplodocid sauropods (and then Dyslocosaurus is a possible candidate). The impressions of the claw and digits curve laterally, a feature commonly observed in sauropod tracks. Manus prints are large. In manus (hand) prints from Mill Canyon, the pollex (thumb) is notably well developed and clearly preserved. Thus, the affiliation of Brontopodus to titanosaurids or diplodocids remains unclear.
Brontopodus tracks occur in a range of locations and geological periods, including the Middle Jurassic of Portugal, the Late Jurassic Morrison Formation and the Early Cretaceous Cedar Mountain Formation in the USA, the Early Tithonian of France, the Nemegt Formation of Mongolia, and the Jiaguan Formation in China dating to the Early Cretaceous.
Breviparopus is an ichnogenus attributed to the tracks of an unidentified sauropod. The footprints reach up to 115 cm in length and 90 cm in width, suggesting an estimated body length of around 34 meters for the trackmaker.
The tracks exhibit high heteropody. The hind footprints (pes) are sub-elliptical, while the front footprints (manus) are kidney-shaped, with all claw marks pointing outward. Based on the shape and features of the tracks, researchers suggest that a diplodocid, titanosaurid, or brachiosaurid could have made the footprints.
The narrow trackway, outward-facing claw marks, and the age of the rocks suggest the tracks likely belonged to a giant diplodocid. However, the presence of a small, medially directed thumb-claw impression raises the possibility of a brachiosaurian origin.
These footprints date back to either the Middle Jurassic (Oxfordian stage) or the Early Cretaceous (Hauterivian stage). The site is located in the present-day Atlas Mountains of Morocco.
Teratopodus represents a set of well-preserved titanosaur tracks with claw impressions. The pes prints are sub-oval, featuring a slightly blunt, V-shaped heel and three prominent, outward-pointing claw impressions corresponding to digits I, II, and III. The manus impressions are symmetrical and kidney-shaped, with a slightly concave posterior margin.
The trackway shows a medium gauge and a moderate degree of heteropody. The tracks, assigned to Teratopodus malarguensis, were likely left by small- to medium-sized titanosaurs, estimated to have reached lengths of 11 to 14 meters.
These footprints date to the middle Campanian stage of the Late Cretaceous, Argentina.
Parabrontopodus. An ichnogenus of a four-legged dinosaur sauropod, most likely diplodocids or closely related forms. The tracks are large but relatively shallow, suggesting the trackmakers were massive yet not exceptionally heavy for their size.
The trackways are narrow gauge, with footprints positioned close to the midline. Pes impressions range from 50 to 90 cm in length, are elliptical, are longer than they are wide, and show an outward rotation of the long axis. The pes track often preserves clear digit and claw impressions, with the claws consistently oriented laterally. The manus prints are semicircular and noticeably smaller compared to the pes impressions.
Romania (Early Jurassic), Colorado (Late Jurassic), France (Jurassic, Late Tithonian), Italy (Jurassic), Portugal (Late Jurassic, Kimmeridgian, Tithonian), Switzerland (Jurassic, mid-Kimmeridgian), and Spain (Cretaceous, lower Neocomian).
Other Quadrupeds: From Ankylosaurs to Ceratopsians
Though most well-known dinosaurs were bipedal, some walked on all fours—at least part of the time. Iguanodonts, for example, were capable of switching between two-legged and four-legged walking. Their footprints reveal wide, blunt three-toed hind feet and five-fingered front feet. Many tracks suggest they walked with an inward, pigeon-toed stance.
Quadrupedal dinosaurs—including stegosaurs, ankylosaurs, and ceratopsians—left diverse pes and manus impressions, often tridactyl, tetradactyl, or pentadactyl. Tracks of quadrupeds such as ceratopsians (horned dinosaurs) and ankylosaurs (armored dinosaurs) are much rarer. Their footprints share a similar structure, with four toes on the back feet and five on the front.
Stegosaur tracks are even scarcer, and surprisingly, none matches the known skeletal structure of stegosaur feet exactly. Five-fingered manus prints are associated with three-toed footprints. This five-fingers/three-toes combination occurs only in stegosaurs. Stegosaur tracks range from kidney-like to more rounded forms, while ankylosaurs typically left stellate tracks.
Ceratopsian footprints are rare but show distinct tetradactyl pes and manus prints. This puzzle keeps paleontologists guessing as they continue to uncover new clues about dinosaur locomotion and behavior. Despite variations, the long-lasting similarities in many dinosaur tracks present challenges in definitively identifying trackmakers. Consequently, this complexity highlights the need for careful ichnological analysis when interpreting fossilized footprints.
Some Dinosaur Tracks of Stegosaurids, Ankylosaurids, and Ceratopsids
Deltapodus. Stegosaur plantigrade tracks. The pes prints are characteristically subtriangular, featuring three short, rounded, and blunt digits positioned anteriorly. The manus impressions are crescent-shaped, occasionally showing a trace of the pollex.
Indeed, identifying these tracks can be challenging, as their overall morphology often resembles that of sauropod footprints. The trackways are quadrupedal, with mesaxonic pes prints that are longer than they are wide.3 Several tracksites suggest that Deltapodus trackmakers exhibited gregarious behavior.
Ichnologists have documented Deltapodus tracks at multiple sites across Europe, North and South America, Africa, and Asia, dating from the Middle Jurassic to the Early Cretaceous.
Furthermore, some researchers have proposed that certain tracks from the Late Cretaceous Lameta Formation in western India could also belong to Deltapodus, which would suggest that stegosaurs persisted into the Maastrichtian—the final stage of the Cretaceous. However, this interpretation remains debated, and confirmation will require corresponding skeletal evidence. At present, the last undisputed stegosaur fossils date from the Early Cretaceous.
Stegopodus. Medium to large three-toed footprints left by a digitigrade semibipedal dinosaur. The toes are very short, wide, and blunt, widely divaricated. They extend only slightly beyond the hypex. The pes prints are mesaxonic and consistently asymmetrical.4 The find preserved the tracks of the front legs. The manus impressions are four-toed, entaxonic, and subtriangular in outline.
Upper Jurassic (Kimmeridgian) of Utah (Morrison Formation), Spain (Tereñes Formation), and Poland (Bałtów Coral Limestone). Fossil evidence confirms that stegosaurs had four digits on their forefeet and three weight-bearing digits on their hind feet.
Tetrapodosaurus. Ankylosaur footprints, gracile, relatively long-toed. The pes prints are four-toed and longer than they are wide. The toe impressions are short, barely extending beyond the main foot pad, and end in rounded ungual traces. Toes I and V are significantly shorter than the central toes, II and III.
Trackway analysis suggests the trackmakers moved at speeds ranging from 1 to 3.7 km/h.
Lower Cretaceous of England, Isle of Wight; Mid-Cretaceous (Albian–Cenomanian), Colorado and Alaska; Lower Cretaceous (Aptian) and early Late Cretaceous (Cenomanian), Canada.
Ceratopsipes. These quadrupedal tracks contain imprints of manus and pes. The tracks are large, 60 cm long and 80 cm wide. Potentially, this dinosaur could be a very large ceratopsid, up to 12 m long. Triceratops or Torosaurus could have left the tracks, as the sediments in the same formation nearby contain their remains.
Late Cretaceous (Maastrichtian), lower part of the Laramie Formation in Colorado.
Identifying Dinosaur Trackmakers
One of the main tasks in ichnology is identifying the taxon of trackmakers. Figuring out which species made specific dinosaur tracks is a complex puzzle. Paleontologists use three main methods to match tracks to their makers: phenetic, coincidence, and synapomorphy-based correlations.5
Phenetic correlation is the simplest and most direct method, comparing fossil footprints with known dinosaur feet. This technique has been used since the 19th century and remains common today. Researchers often overlay foot skeletons onto fossil tracks to check for similarities. More advanced statistical methods now refine these comparisons by finding homologous points between feet and footprints.
Coincidence correlation matches tracks with dinosaurs that lived in the same place and time. For example, large theropod tracks from Late Cretaceous North America usually link to tyrannosaurs because these were the only massive predators in that region at the time. Similarly, robust Jurassic tracks in Europe typically attribute to megalosaurs. This approach is particularly useful for older tracks, such as those from the Triassic, when dinosaur diversity was lower.
Synapomorphy-based correlation is the most precise but also the hardest to apply. It relies on shared anatomical traits between footprints and dinosaur feet. For instance, titanosaurs had tiny or absent claws on their front feet, so their tracks should lack claw impressions. Some sauropod footprints from the Iberian Peninsula fit this pattern, showing a horseshoe shape without claw marks. However, analyzing footprints and feet together is challenging, making this method less commonly used. This method is applicable if the corresponding skeletal synapomorphies are already available.
The most reliable trackmaker identification happens when all three methods align. Thus, Late Cretaceous sauropod tracks are linked to titanosaurs because their shape matches sauropod feet (phenetic correlation), titanosaurs were the only sauropods alive at the time (coincidence correlation), and their footprints show distinctive wide-gauge spacing with missing front claws (synapomorphy correlation).
Some researchers take a broader approach, considering how foot structure, locomotion, and track formation influence footprint shape. Studying how dinosaurs walked and how their feet contacted the ground can help refine identifications, especially for species with similar foot anatomy.
The only way to be completely certain of a trackmaker is to find a dinosaur fossil at the end of its trackway—a rare occurrence. One of the closest cases is a Protoceratops skeleton found next to a footprint that closely matches its foot, possibly the first direct evidence linking a track to its trackmaker.
Autopods Soft Anatomy
Dinosaurs made footprints with the soft tissues of their feet, preserving details about their skin, scales, and claws. Skin impressions found in tracks of sauropods, theropods, ornithopods, and ankylosaurs reveal rounded to polygonal patterns indicative of scaly skin. These impressions can appear as natural casts or direct imprints and vary by species. Until recently, there was no information about the skin impressions of ceratopsids, but now there are such findings.
Another kind of skin trace is the longitudinal grooves along track edges that indicate foot movement within the substrate, offering insights into dinosaur locomotion. Such traces help reconstruct limb movements, as seen in tracks from the Upper Jurassic-Lower Cretaceous of the Iberian Peninsula.
Claw traces at the ends of digits differ by dinosaur group. Theropods and basal ornithischians/ornithopods had sharp claw marks; sauropods typically had three to four, while large ornithopods, thyreophorans, and ceratopsians had blunt claw traces. These impressions reflect the protective corneous sheath extending beyond the bony claw, similar to modern birds.
Well-preserved tridactyl tracks show pad impressions under toes and metatarso-phalangeal joints. These footpads absorbed shock, distributed weight, and stored elastic energy. Their placement aligns with phalanges, with two configurations: arthral (pad midpoint at the joint) and mesarthral (midpoint within the phalanx). As a result, a single footpad can cover multiple bones, multiple pads can overlap a single bone, and gaps may appear in the middle of bones rather than at the joints. Recent studies on theropod scale distribution support this arthral pattern, particularly in the Early Cretaceous carcharodontosaurid Concavenator.
Some tracks preserve impressions beyond the feet, including metapodium, feathers, or ischium traces, providing further anatomical insights.
Stance during Locomotion
Dinosaur tracks provide key insights into dinosaur locomotion. Trackways confirm that sauropods and large ornithischians (ceratopsians, thyreophorans) were quadrupedal, while theropods and small ornithischians were bipedal. Some dinosaurs, like basal sauropodomorphs, iguanodonts, and basal thyreophorans, displayed facultative quadrupedalism, switching between bipedal and quadrupedal movement depending on whether they were grazing lazily (quadrupedal) or moving more quickly (bipedal).
Theropods were predominantly bipedal, though some evidence suggests occasional quadrupedal tracks (these are mostly resting posture marks). Sauropodomorphs, however, evolved from bipedal ancestors to quadrupedal sauropods. For instance, scientists reported bipedal and quadrupedal sauropodomorph trackways from the Late Triassic and Early Jurassic. Early sauropod trackways were fully quadrupedal and narrow-gauge, but by the Middle Jurassic, both narrow- and wide-gauge tracks coexisted. Wide-gauge trackways, associated with titanosaurs, became dominant in the Late Cretaceous.
Basal ornithischians moved both bipedally and quadrupedally, while thyreophorans (stegosaurs and ankylosaurs) and ceratopsians were strictly quadrupedal. Ornithopods initially left bipedal trackways, but as they evolved into larger forms (iguanodontians), manus prints became more frequent, indicating occasional quadrupedal locomotion.
Speed of Displacement
Dinosaurs, like other terrestrial vertebrates, could move at different gaits with varying speeds. There is evidence of dinosaurs running at several tracksites. The preservation of these dinosaur tracks provides clues about their speed, gait, and the various terrains they traversed. A ratio between stride length and acetabular height of less than 1.9 indicates walking; a ratio between 2 and 2.9 indicates trotting; and a ratio greater than 3 indicates running. Theropod dinosaurs were some of the fastest runners of their time, and their fossilized dinosaur tracks give us clues about their top speeds.
Trackways in Utah (Lower Jurassic) reveal some of the highest recorded speeds, estimating theropods ran at 39–50 km/h. Similarly, trackways in Texas (Lower Cretaceous) estimate theropods ran at 34–43 km/h. More recent discoveries of two theropod running trackways in La Rioja, Spain, indicate speeds of 23–37 km/h and 32–45 km/h. Interestingly, these record-breaking tracks all belong to dinosaurs with similar-sized feet, measuring 29–39 cm in length. This evidence suggests that mid-sized theropods were among the best sprinters.
Biomechanical models, which use musculoskeletal reconstructions and physics-based calculations, predict even higher possible speeds. In this regard, two options arise: either these models overestimate the dinosaurs’ true limits, or we have yet to find trackways that capture a theropod running at full capacity. While fossilized footprints provide real-world evidence, they may not always reflect a dinosaur’s absolute top speed. Future discoveries might reveal even faster footprints—or confirm that these ancient sprinters had already reached their limits.
Digitigrade locomotion and narrow trackways (both common features of bipedal dinosaur trails) also suggest cursorial animals and efficient locomotion. Some bipedal trackways are so narrow that the tracks almost form a straight line. The small digit divarication typical of small theropod tracks is also indicative of agile animals. Overall, track evidence suggests that bipedal dinosaurs went about their business at a leisurely pace most of the time but were capable of running fast when the need arose. These conclusions coincide well with recent work on dinosaur anatomy and biology. Even sauropod trackways are relatively narrow in comparison to reptiles such as lizards or turtles. It indicates that although these dinosaurs could not run, they were capable of moving quickly enough.
Could Dinosaurs Swim? Evidence from Fossilized Dinosaur Tracks
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Swimming traces belong to the ethological class of Natichnia trace fossils.
Most land animals can move through water, even if they lack adaptations for swimming. However, true swimming leaves little trace, as a fully buoyant animal wouldn’t interact with the river or lake bed. That’s why “swim tracks” are particularly fascinating—they form when a partially submerged animal makes contact with the underwater surface, typically leaving behind faint footprints or scratch marks.
Swim dinosaur tracks share distinctive features: elongated, claw-like marks, irregular patterns, and sometimes deep grooves from animals kicking off the substrate. These tracks link to various vertebrates from the Paleozoic to the Cenozoic, including dinosaurs.
There are two main types of swim tracks. Buoyancy tracks occur when an animal floats near the surface, lightly touching the bottom with its toes. These are typical of bipedal dinosaurs like theropods and ornithopods, but are also found in some sauropods, ankylosaurs, and stegosaurs. Such tracks are sub-parallel, long, slender grooves, and researchers usually attribute them to Characichnos. Notable examples have been found in Lower Cretaceous sites in La Rioja, Spain.
Punting tracks result from bottom walking, where an animal pushes off the ground to propel itself forward. Several extinct and extant tetrapods, such as crocodiles, turtles, and hippopotamuses, exhibit this behavior, and researchers have identified it in undetermined Permian vertebrates and Early Cretaceous bipedal dinosaurs from Spain’s Cameros Basin.
These fossilized swim tracks suggest that, while dinosaurs weren’t fully aquatic, they could navigate watery environments in ways similar to modern reptiles and large mammals.
Characichnos. Swim tracks that consist of elongate, parallel to sub-parallel ridges or “scrape marks” that occur without walking traces. Ridges may be straight, gently curved, or slightly sinuous. It includes a single species, Characichnos tridactylus, known from prints found in the Middle Jurassic United Kingdom (Saltwick Formation). Possible tracemakers: dinosaurs, crocodilians, chelonians, and amphibians. A «punting» tetrapod, meaning that the animal was drifting or partially buoyant in a body of water and touching or pushing off from the ground with the feet, created Characichnos traces.
Courtship. How Was Their Mating?
Many animals engage in courtship rituals to attract or secure a mate for reproduction. This type of behavior is extremely difficult to identify in the fossil record, and even more so in the ichnological record.
Lockley et al. reported numerous large scratch marks, up to 2 meters in diameter, at several Cretaceous sites in Colorado (USA). Large theropods most likely made these footprints, as evidenced by their morphology. Furthermore, these traces probably link to territorial behavior or courtship activities during the breeding season, possibly in proximity to nesting colonies. These scratches might indicate stereotypical avian-like behavior, previously unknown among Cretaceous theropods.
However, Moklestad and Lucas (2023) offered an alternative interpretation, proposing the behavior could instead relate to digging activities associated with nest construction.
Gregarious Behavior. Were Dinosaurs Social?
Did dinosaurs live in groups, or were they solitary wanderers? While fossilized bones can offer some insights, footprints provide one of the clearest pieces of evidence for gregarious behavior. Tracks found in the same location, moving in parallel in the same direction, with similar sizes, spacing, and speed values, suggest that dinosaurs may have traveled together in herds.
Evidence of social behavior has been identified in various dinosaur groups, including theropods, ornithopods, sauropods, and possibly stegosaurs. A well-known example comes from the Las Cerradicas tracksite (Late Jurassic, Spain), where parallel ornithopod and sauropod trackways indicate herd movement. Similarly, the Fuentesalvo tracksite (Early Cretaceous, Spain) preserves multiple parallel ornithopod tracks, further supporting the idea of group travel.
Another clue comes from dense accumulations of footprints, where numerous tracks of the same type appear in a confined area. For example, at the Soto 2 tracksite, a cluster of small quadrupedal tracks suggests a gathering of young dinosaurs, possibly moving together for protection.
While footprints alone can’t confirm complex social structures, they strongly suggest that at least some dinosaurs moved and lived in groups, much like many modern animals do today.
How Did Dinosaurs Live Together? Clues from Footprints
Fossilized footprints provide a glimpse into how dinosaurs shared their environments, though determining whether different species coexisted in the same place at the same time is challenging. While tracksites often contain footprints from multiple animals, proving these animals made them simultaneously (trackway synchrony) is difficult.
The preservation window—the time a surface remains soft enough to record footprints before hardening—affects the interpretation of tracksites. Short preservation windows, like those in ponds or floodplains, suggest animals made footprints within a short period, likely because they lived there. Long preservation windows, such as lakeshores or coastal lagoons, accumulate tracks over extended periods, reflecting a broader ecological community rather than direct interactions. This concept is similar to time averaging in fossil studies.
A compelling idea is that dinosaurs of different species, like modern wildebeests and zebras, moved together in mixed herds. Some tracksites, such as those showing ornithopod and sauropod footprints on the same surface, suggest possible coexisting groups. However, true synchronicity remains uncertain because some tracks overlap, indicating different times of creation. While footprints hint at dinosaur interactions, confirming whether they truly lived side by side requires more evidence.
Where Dinosaurs Wandered. Insights from Fossilized Footprints
Dinosaurs thrived in diverse environments, and their fossilized tracks reveal their presence in riverbeds, lakes, deserts, coastal regions, and even volcanic landscapes. Analyzing the context of these dinosaur tracks contributes to a broader understanding of the geographic distribution of dinosaurs, illustrating how these magnificent animals roamed the Earth. These footprints provide valuable clues about ancient ecosystems, revealing details like water levels, sediment conditions, and even lake chemistry.
To accurately use footprints as environmental indicators, scientists must first determine the formation and preservation processes of tracks. Tracks can appear in different ways—some as true tracks (the original footprint), while others are underprints (deeper layers disturbed by foot pressure), natural casts, or deep penetrative tracks. A single tracksite can contain multiple overlapping footprints from different sediment layers, making analysis complex.
A major breakthrough in paleoenvironmental studies came from Seilacher’s ichnofacies model, initially applied to marine invertebrates, which identified recurring fossilized traces linked to specific habitats. Later, Lockley et al. (1994) extended this concept to dinosaur tracks. He found that certain track types appeared repeatedly in specific environments. For instance, Caririchnium tracks commonly appear in ancient shorelines, while Parabrontopodus tracks often occur in lake margins, forming part of the Brontopodus ichnofacies, which represents coastal and lacustrine environments.
However, interpreting vertebrate ichnofacies remains challenging because the factors influencing dinosaur movement—such as water salinity, oxygen levels, and sediment stability—are not yet fully understood. Despite these uncertainties, fossilized footprints continue to offer a fascinating glimpse into the landscapes where dinosaurs once roamed.
Dinosaur Tracks: Conclusion
Since the first dinosaur discoveries, scientists and enthusiasts have pondered how these creatures lived. Early paleontologists, like Richard Owen (1841), believed some dinosaurs were aquatic. Sauropods were thought to inhabit water due to their massive size, and hadrosaurs were once considered amphibious, feeding in swamps.6
New technologies have made it possible to learn a lot about the life of dinosaurs with respect to their locomotion, functional anatomy, and behavior.
Fossilized footprints add another dimension to this research, offering clues about foot anatomy, movement, and social interactions. Tracks also help reconstruct ancient environments, revealing details about moisture levels, shoreline orientations, and even possible dinosaur herds.
Despite these advances, many mysteries remain. Could footprints provide insights into dinosaur reproduction, flight evolution, or top running speeds? As ichnology continues to evolve, so too will our understanding of how these incredible creatures once roamed the Earth.
- Glen J. Kuban (1994-2015). An Overview of Dinosaur Tracking. ↩︎
- «Únicas en el mundo»: así es el parque con increíbles huellas de dinosaurios que se abrirá en Mendoza ↩︎
- Fernández-Baldor et al, 2015. Unusual sauropod tracks in the Jurassic-Cretaceous transition. Cameros Basin (Burgos, Spain) ↩︎
- Fernández-Baldor et al, 2015. Unusual sauropod tracks in the Jurassic-Cretaceous transition. Cameros Basin (Burgos, Spain) ↩︎
- Díaz-Martínez, Citton, and Castanera, 2023. What do their footprints tell us? Many questions and some answers about the life of non-avian dinosaurs. ↩︎
- The history of the study of vertebrate footprints is most fully described in the work of William A. S. Sarjeant «The Study of Fossil Vertebrate Footprints A Short History and Selective Bibliography». ↩︎
