February 2nd, 2025 
Riffin @WFS,World Fossil Society, Athira,Riffin T Sajeev,Russel T Sajeev
The fossilised neck bone of a flying reptile unearthed in Canada shows tell-tale signs of being bitten by a crocodile-like creature 76 million years ago, according to a new study published today [23 January] in the Journal of Palaeontology.
The juvenile pterosaur vertebra, discovered in Dinosaur Provincial Park, Alberta, bears a circular four-millimetre-wide puncture mark from a crocodilian tooth.
TMP 2023.012.0237 in dorsal (1, 7, 13), ventral (2, 8, 14), right lateral (3, 9, 15), left lateral (4, 10, 16), anterior (5, 11, 17), and posterior (6, 12, 18) views. Upper images (1–6) show bone surface color, middle images (7–12) are ammonium chloride powder-coated, lower images (13–18) are schematic line drawings. For the line drawings (13–18), light and medium gray indicates bone surface, hatches indicate broken bone surface, light stipples indicate matrix infill creating natural internal mold, and dark stipples indicate matrix infill with no specific form. apf, accessory pneumatic foramen; lpf, lateral pneumatic foramen; nc, neural canal; ns, neural spine; tr, trace (i.e., feeding trace/tooth mark).
Researchers from the Royal Tyrrell Museum of Palaeontology (Canada), the University of Reading (UK) and the University of New England (Australia) say this rare evidence provides insight into predator-prey dynamics in the region during the Cretaceous Period.
The discovery was made during an international field course that took place in July 2023, led by Dr Brian Pickles from the University of Reading.
Ammonium chloride coated images (1, 2), CT-scan slice (3), and digital render (4) of TMP 2023.012.0237: (1) entire element in ventral view (anterior at right), with gray area approximating the missing portion; (2) detail of anterior end with tooth mark; (3, 4) outputs of CT-scan data: (3) two-dimensional slice through the tooth mark at plane indicated in 2.3; (4) solid three-dimensional render of the element. Solid vertical lines in (1, 2) show plane of slice in (3). Dashed lines in (3) show missing extent of bone surface at the point of the trace.
Dr Caleb Brown from the Royal Tyrrell Museum of Palaeontology is the lead author of the paper.
He said: “Pterosaur bones are very delicate — so finding fossils where another animal has clearly taken a bite is exceptionally uncommon. This specimen being a juvenile makes it even more rare.”
Dinosaur Provincial Park has produced some of the most important dinosaur fossil discoveries ever made.
The punctured vertebra belongs to a young Azhdarchid pterosaur (Cryodrakon boreas), with an estimated wingspan of two metres.
Adults of this species would have been as tall as a giraffe with a wingspan in the region of 10m.
The researchers used micro-CT scans and comparisons with other pterosaur bones to confirm the puncture is not a result of damage during fossilisation or excavation, but an actual bite.
Dr Brian Pickles from the University of Reading and co-author of the paper said: “Bite traces help to document species interactions from this period. We can’t say if the pterosaur was alive or dead when it was bitten but the specimen shows that crocodilians occasionally preyed on, or scavenged, juvenile pterosaurs in prehistoric Alberta over 70 million years ago.”
The paper also shows that this new bone documents the first evidence in North America of ancient crocodilians opportunistically feeding on these giant prehistoric flying reptiles. Other examples of Azhdarchid bones with possible crocodilian bites have previously been found in Romania.
Journal Reference: Caleb M. Brown, Phil R. Bell, Holly Owers, Brian J. Pickles. A juvenile pterosaur vertebra with putative crocodilian bite from the Campanian of Alberta, Canada. Journal of Paleontology, 2025; 1 DOI: 10.1017/jpa.2024.12
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