Footprint type
Byakudansauropus
Byakudansauropus is a footprint type: the name is for the fossil footprints themselves. The animal that made them is not known for certain. Its footprints are found in rocks 137.1–121.4 million years old in Japan.
Confidence labels are switched off. Facts with low confidence, or where sources disagree, still carry a small dot: tap it for the reason.
At a glance
Data as of 12 October 2026- Named by
- Azuma and Takeyama 1991
medium
medium: Only PBDB gives this; nothing contradicts it.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Described in
- Y. Azuma, K.-i. Takeyama (1991). Dinosaur footprints from the Tetori Group, central Japan—research of dinosaurs from the Tetori Group (4). Bulletin of the Fukui Prefectural Museum 4: 33–51.
medium
medium: Only PBDB gives this; its author and year match the naming authority (Azuma and Takeyama 1991).Sources
Given by: Paleobiology Database. The publication the Paleobiology Database gives as the authority for this genus name, usually the one that first named and described it.
- Type species
- Byakudansauropus shiraminensis
medium
medium: Only PBDB gives this; nothing contradicts it.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Dated to
- Valanginian to Barremian, 137.1–121.4 million years ago
medium
medium: Only PBDB gives this; nothing contradicts it.Omnisaura calculation137.1–121.4 million years ago, from its dated fossil recordslow
low: Omnisaura's calculation from only 1 dated record(s).Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Found in
- Japan
low
low: Only one PBDB record.Sources
Given by: Paleobiology Database. How it was chosen: Union of all sources (ISO 3166).
- Rock formations
- Akaiwa
low
low: Only one PBDB record.Sources
Given by: Paleobiology Database. How it was chosen: Canonical names, automatic and editor-approved matches applied.
- Parent group
- Theropoda
medium
medium: Only PBDB gives this; nothing contradicts it.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Known from
- Footprints and traces
Sources
Given by: Paleobiology Database (what the name was based on).
- Made by
- Not known for certain. Footprints rarely show which animal made them.
Gaps are answers
What isn't known yet
- The animal that made them: not known for certain, as for most footprint types.
- Order: no source we use gives it yet.
- Family: no source we use gives it yet.
- Common names: no source we use gives it yet.
- What it was named after: no source we use gives it yet.
- Resting on one source: 5 facts come from a single source with nothing against them (rated medium): name (PBDB); authority (PBDB); type species (PBDB); parent group (PBDB); age (headline) (PBDB).
Size, diet and behaviour aren't covered yet. Omnisaura leaves them out rather than guess.
Where sources disagree
None open. Where our sources overlap, they agree on everything shown here.
Did it meet…?
No. Byakudansauropus had gone at least 37.8 million years before Tyrannosaurus appears in the fossil record.
Going by the ages and rock formations of their dated fossils, as on the map. Compare their fossil sites on the map.
Found in the same rocks
Genera and other fossil types from the same formations, from rocks of the same age.
Same parent group
Other genera in Theropoda with a full profile.
Credits
Where this page comes from
- Paleobiology DatabaseCC BY 4.0 · fossil records, ages, classification
- OmnisauraOmnisaura editorial · confidence levels and gaps
- PaleoMAP PaleoCoastlines (Kocsis and Scotese 2021)CC BY 4.0 · ancient coastlines on the small map
- Natural EarthPublic domain · today's coastlines