December 23, 2024

Locked in Mortal Combat: Unusual Fossil Shows Mammal Attacking a Dinosaur

Fossil showing the knotted skeletons of Psittacosaurus (dinosaur) and Repenomamus (mammal) and their interaction right before death. KEEP IN MIND: The scale bar equals 10 cm. Credit: Gang Han
A 125-million-year-old fossil, showing a meat-eating mammal attacking a dinosaur, challenges the long-standing belief that Cretaceous dinosaurs dealt with very little dangers from mammals. This substantial finding provides brand-new insights into ancient predator-prey characteristics.
A Glimpse into Prehistoric Predation
Chinese and canadian scientists have actually discovered an uncommon fossil, going back approximately 125 million years, that illustrates a meat-eating mammal attacking a larger plant-eating dinosaur. This amazing discover provides a picture of a significant minute frozen in time.
Illustration revealing Repenomamus robustus as it assaults Psittacosaurus lujiatunensis minutes before a volcanic debris circulation buries them both, ca. 125 million years back. Credit: Michael Skrepnick
” The 2 animals are secured mortal fight, intimately intertwined, and its among the first proof to show real predatory habits by a mammal on a dinosaur,” explains Dr. Jordan Mallon, palaeobiologist with the Canadian Museum of Nature and co-author on the study released on July 18 in the journal Scientific Reports.

The fossils presence challenges the standard view that dinosaurs had couple of dangers from their mammal contemporaries during the Cretaceous, when dinosaurs controlled. The unique fossil is now housed in the collections of the Weihai Ziguang Shi Yan School Museum in Chinas Shandong Province.
Information of bigger fossil, showing Repenomamus (mammal) biting the ribs of Psittacosaurus (dinosaur). Credit: Gang Han
Details of the Fossil Find
The fossil captures a meat-eating, badger-like mammal, called Repenomamus robustus, in the act of assaulting a Psittacosaurus, a dinosaur about the size of a large canine. Psittacosaurs, which lived in Asia during the Early Cretaceous period from about 125 to 105 million years earlier, are amongst the earliest known horned dinosaurs. Although not big by dinosaur standards, Repenomamus robustus was one of the most significant mammals of the Cretaceous duration– a time when mammals had not yet achieved global supremacy.
Prior to this discovery, it was understood that Repenomamus took advantage of dinosaurs including Psittacosaurus, due to the presence of fossilized baby dinosaur bones found in the mammals stomach.
” The co-existence of these two animals is not brand-new, but whats new to science through this fantastic fossil is the predatory behavior it reveals,” states Mallon.
Life restoration showing Psittacosaurus (dinosaur) being attacked by Repenomamus (mammal), 125 million years earlier. Credit: Michael Skrepnick
Unearthing the Evidence
The fossil, gathered in Chinas Liaoning Province in 2012, is remarkably unspoiled with almost total skeletons of both animals. This level of preservation is because of its origin in the Liujitun fossil beds, an area appropriately called “Chinas Dinosaur Pompeii.”
This name references the multitude of maintained fossils of dinosaurs, small mammals, lizards, and amphibians in the location– creatures that were rapidly buried by mudslides and debris from volcanic eruptions. Canadian Museum of Nature mineralogist Dr. Aaron Lussier verified the presence of volcanic material in the rock matrix of the fossil under study.
The Psittacosaurus-Repenomamus fossil was in the care of study co-author Dr. Gang Han in China, who brought it to the attention of Canadian Museum of Nature palaeobiologist Xiao-Chun Wu. When he saw it, Dr. Wu has actually worked with scientists in China for decades and knew it was special.
Fossil showing the knotted skeletons of Psittacosaurus (dinosaur) and Repenomamus (mammal), with amplified areas showing the mammal biting the dinosaurs ribs, and gripping its prey. Scale bar equals 10 cm. Credit: Gang Han
Analysis of the Predation Scene
Upon close assessment, the fossil set reveals the Psittacosaurus hitting the deck, its hindlimbs folded on either side of its body. The Repenomamus is seen coiling to the right and sitting atop its victim, gripping the jaw of the bigger dinosaur and biting into its ribs. The mammals back foot is also grasping onto the dinosaurs hind leg. “The weight of the proof suggests that an active attack was underway,” says Dr. Mallon.
The research study group, consisting of Mallon and Wu, dismissed the idea that the mammal was merely scavenging a dead dinosaur. It is not likely that the 2 animals would have become so knotted if the dinosaur had actually already been dead before the mammal found it.
Hillside where the fossil was collected from the Lujiatun Member of the Yixian Formation of northeastern China in 2012. Credit: Gang Han
Modern Analogies and Future Discoveries
Similar situations of smaller sized animals assaulting bigger victim are observed in the modern world. For circumstances, lone wolverines are known to hunt bigger animals like caribou and domestic sheep. In the African savanna, wild pets, jackals, and hyenas will assault victim that is still alive, often leaving them in a state of shock.
” This may be the case of whats depicted in the fossil, with the Repenomamus really eating the Psittacosaurus while it was still alive– before both were killed in the roily aftermath,” discusses Mallon.
The research study team prepares for that the volcanically obtained deposits from the Lujiatun fossil beds in China will continue to provide fresh proof of interspecies interactions, hitherto unidentified from the fossil record.
Recommendation: “An amazing fossil captures the battle for presence throughout the Mesozoic” by Gang Han, Jordan C. Mallon, Aaron J. Lussier, Xiao-Chun Wu, Robert Mitchell and Ling-Ji Li, 18 July 2023, Scientific Reports.DOI: 10.1038/ s41598-023-37545-8.

Fossil revealing the entangled skeletons of Psittacosaurus (dinosaur) and Repenomamus (mammal) and their interaction simply before death. The fossil records a carnivorous, badger-like mammal, called Repenomamus robustus, in the act of assaulting a Psittacosaurus, a dinosaur about the size of a large dog. Not large by dinosaur requirements, Repenomamus robustus was one of the biggest mammals of the Cretaceous duration– a time when mammals had actually not yet achieved international supremacy.
Fossil showing the entangled skeletons of Psittacosaurus (dinosaur) and Repenomamus (mammal), with magnified areas showing the mammal biting the dinosaurs ribs, and grasping its prey. It is not likely that the two animals would have become so knotted if the dinosaur had currently been dead before the mammal found it.