Paleontologists have discovered the tracks of a 5-m- (16.4-foot-) long troodontid at the Longxiang locality in the Chinese province of Fujian.
The Longxiang tracksite includes twelve two-toed tracks that fall into two morphologies, differentiated by both size and form.
The smaller tracks, around 11 cm (4.3 inches) long, belong to the previously known ichnogenus Velociraptorichnus.
The larger tracks, up to 36 cm (14.2 inches) long, establish a new ichnospecies named Fujianipus yingliangi.
Based on their size, the track-maker had an estimated hip height of over 1.8 m (5.9 feet), a size comparable to that of the largest known deinonychosaurs, i.e., Austroraptor and Utahraptor.
“When people think of raptor dinosaurs, they most likely think of those in the Jurassic Park movies — human-sized, muscly, aggressive hunters,” said University of Queensland paleontologist Anthony Romilio.
“But these tracks were left by a much slimmer and brainier group in the family Troodontidae, which emerged in the Late Jurassic period around 95 million years ago.”
“This raptor was around 5 m long with 1.8-m-long legs, far exceeding the size of the raptors depicted in Jurassic Park. Imagine something like that coming at you at full speed.”
“The tracks were compared with other known two-toed dinosaur tracks from across Asia, North and South America and Europe.”
Details of Fujianipus yingliangi tracks preserved at the Longxiang tracksite, China. Image credit: Xing et al., doi: 10.1016/j.isci.2024.109598.
“We found this track type is distinct in shape, making it quite unique,” he said.
“The concept of large troodontids has only recently emerged in the paleontological community.”
“Bones discovered in Alaska hint at a trend toward gigantism near the ancient Arctic circle, an area with potentially less species competition due to extended periods of winter darkness.”
“But our findings suggest these raptor giants roamed much further south and were more widely dispersed.”
“Interestingly, some of our research team has also worked on the world’s tiniest dinosaur footprints — raptor tracks in South Korea that are just one centimeter long.”
“It just goes to show the incredible size range among raptor dinosaurs, highlighting their adaptability and ecological diversity.”
A paper describing the findings was published in the journal iScience.
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Lida Xing et al. Deinonychosaur trackways in southeastern China record a possible giant troodontid. iScience, published online April 24, 2024; doi: 10.1016/j.isci.2024.109598