A newly revealed scientific paper has highlighted the weight loss program of juvenile tyrannosaurs. Writing within the educational journal “Science Advances” the analysis staff report {that a} younger Gorgosaurus consumed the hind limbs from a pair of caenagnathid dinosaurs (Citipes elegans). That is the primary time that abdomen contents have been present in affiliation with a tyrannosaur specimen.
An excellent, well-preserved Gorgosaurus libratus specimen was discovered by Royal Tyrrell Museum of Palaeontology employees within the Dinosaur Provincial Park in 2009. The specimen is a juvenile, regarded as between 5 and 7 years of age. When it died this dinosaur weighed round 335 kilograms, solely about 13% of the mass of an grownup Gorgosaurus.
Abdomen Contents Preserved in a Younger Gorgosaurus
While being cleaned and ready on the Royal Tyrrell Museum of Palaeontology (Alberta, Canada), the partial stays of two small theropods had been found contained in the abdomen cavity. The analysis staff decided that this juvenile tyrannosaur ate the hind limbs of two caenagnathids. Fairly than consuming the entire animal, the younger tyrannosaur solely ate the hind limbs (the meatiest elements of the physique).
Evaluation of the Citipes stays demonstrated that they had been younger animals, maybe twelve months previous. Alongside the Citipes limb bones caudal vertebrae had been found. This implies that there was preferential consumption of the Citipes hind quarters.
The weather highlighted in inexperienced within the illustration (above) are the stays of the primary Citipes particular person the gorgosaur consumed. The weather highlighted in blue are fossilised bones from the second Citipes particular person eaten.
The Identical Meal however Consumed at Completely different Instances
As the weather of the 2 Citipes people are at totally different phases of digestion, the researchers had been capable of conclude that the gorgosaur’s abdomen contents signify two totally different meals. These two juvenile Citipes might have been ingested hours or days aside. The presence of two dinosaurs of the identical species and age within the abdomen contents, ingested at totally different instances, means that younger caenagnathids could have been among the many most well-liked prey of juvenile gorgosaurs.
This specimen is the primary to supply direct proof that younger gorgosaurs had totally different diets than their grownup counterparts. When totally grown Gorgosaurus would have been an apex predator. Feeding traces preserved on fossil bones point out that Gorgosaurus consumed ceratopsians and duck-billed dinosaurs.
This proof means that tyrannosaurs occupied totally different ecological niches over their lifetime. As younger tyrannosaurs grew and matured, they’d have transitioned from looking small and younger dinosaurs to preying on giant herbivores. This dietary shift probably started across the age of 11, when their skulls and enamel began turning into extra strong.
Image credit score: All the pieces Dinosaur
The image (above) exhibits a reproduction of an grownup Gorgosaurus. The cranium is way more strong and highly effective and the enamel proportionately bigger. The mannequin is from the PNSO Age of Dinosaurs vary.
To view this vary of prehistoric animal figures: PNSO Age of Dinosaurs Fashions and Figures.
A Means of Lowering Intraspecific Competitors
Dietary variations are seen in animals at totally different ontogenic phases in fashionable ecosystems. These variations in weight loss program present a aggressive benefit by lessening intraspecific competitors for assets. Subsequently, such a shift could have allowed juvenile and grownup tyrannosaurs to coexist in the identical setting with diminished battle.
With the ability to occupy totally different ecological niches throughout their lifespan was in all probability a key to the evolutionary success of the Tyrannosauridae.
All the pieces Dinosaur acknowledges the help of a media launch from the Royal Tyrrell Museum of Palaeontology within the compilation of this text.
The scientific paper: “Exceptionally preserved abdomen contents of a younger tyrannosaurid reveal an ontogenetic dietary shift in an iconic extinct predator” by Francois Therrien, Darla Okay. Zelenitsky, Jared T. Voris, Gregory M. Erickson, Philip J. Currie, Christopher L. Debuhr and Yoshitsugu Kobayashi revealed in Science Advances.
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