page_title: Bellatoripes
section_title: Palaeobiology
hierarchical_section_title: Bellatoripes / Palaeobiology
caption_attribution_description: English: Hypothesized pes movement of the track-maker for Bellatoripes fredlundi. The digits were not dragged cranially through the substrate as previously described in theropods footprints. The pes and digits were retracted from the substrate along an opposite trajectory of their entry prior to the pes moving forward in the next step cycle. Arrows indicate trajectory of the foot of Trackway C, print #2 as deduced from entry striations at the point of pes entry (left frame) and exit (center frame) into the substrate.
context_page_description: Bellatoripes is an ichnogenus of footprint produced by a large theropod dinosaur so far known only from the Late Cretaceous of Alberta and British Columbia in Canada. The tracks are large and three-toed, and based on their size are believed to have been made by tyrannosaurids, such as Albertosaurus and Daspletosaurus. Fossils of Bellatoripes are notable for preserving trackways of multiple individual tyrannosaurids all travelling in the same direction at similar speeds, suggesting the prints may have been made by a group, or pack, of tyrannosaurids moving together. Such inferences of behaviour cannot be made with fossil bones alone, so the record of Bellatoripes tracks together is important for understanding how large predatory theropods such as tyrannosaurids may have lived.
context_section_description: The presence of three, parallel Bellatoripes trackways inferred to have been created in a short span of time is suggested to indicate that tyrannosaurids were social, gregarious animals that travelled in groups. Similar suggestions could only be made from skeletal evidence from body fossils alone, such as assemblages of multiple individuals preserved together at one locality. The sedimentary conditions to preserve the tracks implies that they were made within a short span of time, and other tracks at the same site (including those of a hadrosaur and a smaller theropod) are more randomly oriented, implying that the animals were not constrained along the same path by a geographical barrier. Bellatoripes tracks are the first evidence from traces of living tyrannosaurids to support the suggestion that they lived in groups.
  The trackways of Bellatoripes allowed for the speed the track-maker was travelling at to be calculated, using the estimated hip height and stride lengths. This speed was calculated to be around 6.4 kilometres per hour (4.0 mph) to 8.5 kilometres per hour (5.3 mph), and is inferred to represent the preferred walking gait of tyrannosaurid theropods. Similarly, the age of the track-makers could be inferred from the dimensions of the footprints compared to the estimated hip height based upon contemporary tyrannosaurids that likely produced Bellatoripes tracks (Albertosaurus, Gorgosaurus, and Daspletosaurus). The track-makers were estimated to be between 25–29 years old, within the known upper age range of tyrannosaurid lifespans and indicating that the animals were mature adults.
  The fine preservation of the distal digits and small, parallel striations (interpreted as drag marks) within Bellatoripes tracks suggests that the track-makers partially withdrew their feet backwards before stepping forward, leaving the overlying sediment undisturbed. This contrasts with what is typically seen in other theropod footprints, where the tips of the digits drag as they are pulled forward, but is similar to the observed movements of ostrich feet during locomotion.
caption: The hypothesised movements of the Bellatoripes track-maker
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