New research confirms the existence of intraspecific fighting in Triceratops horridus, a species of horned dinosaur that lived in North America some 69 million years ago (Cretaceous period).
The complete restored skeleton of the Triceratops horridus Big John; the fenestra analyzed by D’Anastasio et al. is indicated by the white circle. Image credit: A. Ferrara / I. Briano / D’Anastasio et al., doi: 10.1038/s41598-022-08033-2.
Triceratops horridus was characterized by its large neck frill formed from extended patietal and squamosal skull bones.
It has been suggested that this bony frill served as protection against injuries from other triceratops during fights.
In the new study, Dr. Ruggero D’Anastasio from the ‘G. D’Annunzio’ University of Chieti-Pescara and his colleagues from Italy examined the fossilized remains of Triceratops horridus known as Big John (due to its large size).
The specimen was discovered in 2014 in the Upper Cretaceous Hell Creek Formation in Montana, the United States, from where numerous remains of ceratopsid dinosaurs have been recovered.
The paleontologists found a keyhole-shaped opening (a fenestra) in the right squamosal bone.
The bone surface around the fenestra is irregular and features plaque-like deposits of bone, which could have resulted from inflammation (possibly from infection).
The researchers analyzed samples taken from the larger margin of the fenestra, which reveal that the bone tissue around the fenestra is porous with lots of blood vessels compared to bone tissue further from the fenestra, suggesting that this was newly formed bone.
The bone also showed signs of remodeling, as demonstrated by the presence of little pits known as Howship lacunae.
Together, these features indicate that the fenestra was caused by a traumatic injury but that the bone was healing at the time of Big John’s death.
“The injury was caused by the horn of another triceratops, and occurred at least six months before Big John’s death,” the scientists said.
“Based on these findings, the mechanisms underlying the healing process in dinosaurs appears to be similar to that in mammals.”
The team’s paper was published in the journal Scientific Reports.
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R. D’Anastasio et al. 2022. Histological and chemical diagnosis of a combat lesion in Triceratops. Sci Rep 12, 3941; doi: 10.1038/s41598-022-08033-2
Source link: https://www.sci.news/paleontology/triceratops-combat-injuries-10696.html
