About Baryonyx
| Scientific Name (Genus) | Baryonyx |
| Meaning of Name |
Heavy claw
barys(heavy)[Greek]-onyx(claw)[Greek] |
| Classification | Saurischia, Theropoda, Tetanurae, Spinosauridae |
| Total Length | Approx. 7.5-10m |
| Weight | Approx. 1.2-2t (Estimated from holotype specimen) |
| Diet | Piscivorous and carnivorous (opportunistic predator) |
| Period | Early Cretaceous (Barremian stage, approx. 130 million to 125 million years ago) |
| Sub-classification / Species Name | Baryonyx walkeri |
| Year of Paper Publication | 1986 |
| Genus Name Publication | Charig, A. J.; Milner, A. C. (1986). Baryonyx, a remarkable new theropod dinosaur. Nature, Volume 324. |
Features
Baryonyx was a large theropod that lived in Europe during the Early Cretaceous period (about 130 million to 125 million years ago). Although the discovered fossil (holotype specimen) was an actively growing subadult, it is estimated to have reached a total length of 7.5 to 10 meters and a weight of 1.2 to 2 tons.
Its most prominent feature is its long, narrow snout, similar to modern crocodiles (especially the highly piscivorous gharial). The tip of the mouth widened into a spoon shape, and there was a notch behind it where the tip of the lower jaw fit perfectly. This is considered an adaptation to securely hold onto slippery prey thrashing violently in the water.
It had at least 96 teeth, with very fine serrations suitable for piercing deeply and holding prey. In addition, the lower jaw was densely packed with twice as many teeth as the upper jaw.
The spoon-shaped, laterally expanded structure seen at the tip of Baryonyx's mouth. It is commonly found in spinosaurid dinosaurs that catch fish.
Collection of the Natural History Museum, London
Its forelimbs were extremely strong, and the giant claw on its first digit (thumb), which gave it the name "heavy claw," reached about 31 centimeters in length. This claw was highly curved and is thought to have been used as a powerful weapon for hooking and pulling up giant fish from the water's edge, or pinning down terrestrial prey.
Its neck did not have the strong S-shaped curve typical of general carnivorous dinosaurs, but rather drew a relatively gentle S-curve. The projections of the spine (neural spines) became higher towards the back, suggesting the possibility of a low, muscular hump in the center of the back, rather than a giant sail like its close relative Spinosaurus.
Furthermore, recent brain structure analysis using CT scans has revealed that their brains and sensory organs were not significantly different from those of general terrestrial carnivorous dinosaurs. In other words, it is thought that they adapted to waterside life by specializing the skeleton of their snouts and forelimbs, without dramatically altering their brain structure.
Diet and Walking Posture of Baryonyx
Baryonyx is a very rare dinosaur whose stomach contents were preserved as fossils exactly as they were. A large amount of ancient fish scales and teeth with traces of being dissolved by stomach acid were found in its abdominal region. This made Baryonyx the first theropod in the history of dinosaur research to be confirmed as "piscivorous."
However, that wasn't all. Un-digested bones of a young ornithopod dinosaur (such as the iguanodontian Mantellisaurus) were also found together from the same stomach region. In other words, Baryonyx did not only eat fish, but was also an "opportunistic" predator that hunted small to medium-sized terrestrial animals and scavenged the carcasses of large animals.
Regarding its walking posture, it was once thought that it "walked on four legs like a grizzly bear to catch fish" due to the impression of its strong forelimbs. However, subsequent research revealed that its forelimb joints could not face their palms towards the ground, making quadrupedal walking impossible. Center of gravity calculations using computers have also proven that Baryonyx was a completely "bipedal animal."
In addition, there has been fierce debate in recent years regarding "how they caught fish." For a time, a hypothesis was published that they "submerged their entire bodies in the water and agilely pursued fish" due to their high bone density. However, currently, it is considered physically difficult for them to dive due to strong buoyancy from air sacs (part of the respiratory system) and water resistance against their huge bodies. The most widely accepted theory is that they waded in the shallows and riverbanks on two legs and ambushed prey near the water surface, much like modern herons and brown bears.
History of Discovery and Historical Significance
Baryonyx was discovered in January 1983 by amateur fossil collector William J. Walker at a clay pit in Surrey, England. The giant claw he found was brought to the Natural History Museum in London, leading to a large-scale excavation by a team led by paleontologists Alan J. Charig and Angela C. Milner.
As a result, a skeleton equivalent to about 70% of the entire body was recovered, and it remains one of the most complete skeleton specimens in the world among the Spinosauridae to this day. This great discovery was reported in the media at the time with the nickname "Claws," a play on a famous movie.
In 1986, it was described in the academic journal "Nature" as a new species, Baryonyx walkeri. The specific name "walkeri" was named after its first discoverer, Mr. Walker.
This discovery overturned the conventional wisdom that "large carnivorous dinosaurs = terrestrial apex predators" and scientifically proved for the first time the existence of specialized piscivorous dinosaurs adapted to semi-aquatic environments such as rivers, marking a groundbreaking event (paradigm shift) in the history of dinosaur research.
Baryonyx Stamp and Fossil Gallery
