Grallator (Theropod Footprint)
Grallator sp. • Trace fossil (Ichnofossil); Vertebrate footprint
Geological Period
Lower Jurassic
Estimated Age
190 to 200 million years
Preservation Type
Natural impression / Concave epirelief
Condition Assessment
Fair to Good; the track is shallow and lacks sharp detail in the claw tips, but the tridactyl symmetry is clearly discernible against the weathered matrix
Taxonomic Classification
Ichnophylum: Vertebrata; Ichnoclass: Reptilia; Ichnoorder: Dinosauria; Ichnofamily: Grallatoridae; Ichnogenus: Grallator
Morphological Description
A small, tridactyl (three-toed) footprint. The track is longer than it is wide, showing a distinct V-shape. The middle toe (digit III) is significantly longer than the outer toes (digits II and IV). The impressions are digitigrade, representing the distal parts of the toes and claws of a small theropod dinosaur.
Rock Matrix
Reddish-brown Micaceous Siltstone / Mudstone with iron oxide staining
Formation & Location
Likely Portland Formation or East Berlin Formation of the Newark Supergroup (Connecticut River Valley, USA)
Size & Dimensions
Approximately 4–6 cm in length; typical for small Grallator type tracks which range from 3 to 15 cm
Value & Rarity
Estimated Market Value
$40 - $120 USD
Auction Estimate
$50 - $150 USD
Rarity Assessment
Common; Grallator footprints are among the most frequently discovered dinosaur tracks in Eastern North American red beds
Scientific Significance
Provides evidence of the diversity of small theropod dinosaurs in the Early Jurassic rift basins; useful for paleoenvironmental reconstruction of ancient lake margins and floodplain ecosystems
Preparation Recommendations
No invasive preparation needed. Lightly brush with a soft dry brush. Store in a stable, low-humidity environment to prevent the siltstone from flaking
Notable Features
Classic 'bird-like' dinosaur footprint morphology; the reddish hue is characteristic of 'Red Bed' deposits formed in semi-arid environments