Unraveling the Ancient Mystery: Enigmatic Jawbone Holes in Sue the T. rex Baffle Scientists, Sparking Paleontological Intrigue


Unveiling the Mystery: Unidentified Cavities Discovered in Tyrannosaurus rex’s Jawbone

A recent examination of perplexing abnormalities present in the mandible of Sue, an exceptionally well-preserved and colossal Tyrannosaurus rex specimen, unveils distinct features indicative of the regenerative process in the absence of any infection.

The captivating image shows Dr. O’Connor proudly displaying the skull of Sue the T. rex at the renowned Field Museum. Credit for this remarkable photograph goes to Katharine Uhrich of the Field Museum.


“For decades, the origins of these jawbone holes in Sue have remained a perplexing enigma,” remarked Dr. Jingmai O’Connor, a paleontologist affiliated with the Field Museum of Natural History. “The formation of these holes has eluded our understanding, leading to numerous conjectures and speculations.”

Initially, a hypothesis was put forward suggesting that Sue might have been afflicted by a bacterial infection resembling a fungus. However, subsequent investigations discredited this theory, deeming it improbable. Instead, a re-evaluation proposed the possibility of a protozoan infection affecting this particular individual.

Protozoans are microorganisms characterized by more intricate cellular structures compared to bacteria. They encompass a wide range of organisms that can cause various diseases. One well-known example is trichomoniasis, a common infection caused by the microbe Trichomonas vaginalis. While trichomoniasis primarily affects humans, it is worth noting that other animals can also be susceptible to this condition.

Dr. O’Connor further explained, “Trichomoniasis has been observed in birds, and there is a falcon specimen with jaw damage. This led some paleontologists to speculate that a protozoan similar to Trichomonas could have caused similar damage to Sue.”

“To test this hypothesis, our study aimed to compare the jaw damage in Sue with the effects of Trichomonas infection on other animals.”

To conduct their analysis, Dr. O’Connor and her colleagues meticulously captured high-resolution photographs of the holes in Sue’s jaw and scrutinized them for any indications of bone regeneration.

Furthermore, the researchers compared the characteristics of the holes in Sue’s jaw with evidence of healed fractures in other fossilized skeletons. They also investigated the healed bones surrounding trepanation holes, which were intentionally made in skulls by Inca surgeons and healers in ancient Peru.

The findings yielded compelling results. Dr. O’Connor remarked, “We discovered that Sue’s injuries exhibited remarkable similarities to these other instances of bone injury and subsequent healing. There were distinct signs of bone regeneration in the form of small bone spurs.”

She continued, “Whatever the cause of these holes may have been, it did not prove fatal for Sue. The animal survived long enough for the bones to initiate the repair process, indicating a remarkable resilience.”


The captivating image of the holes in Sue the T. rex’s jaw is credited to Rothschild et al., published in an article with the digital object identifier (DOI) 10.1016/j.cretres.2022.105353.

The researchers also conducted an examination of a bird skeleton that had a documented history of trichomoniasis.

Dr. O’Connor commented on the findings, stating, “While signs of infection were indeed observed in the back of the throat, there were no jaw holes similar to those seen in Sue. Trichomonas or a similar protozoan does not appear to align with the observed evidence.”

The quest to determine the origin of these holes continues, as alternative hypotheses are considered. One possibility suggested by researchers is that the holes could be the result of bite marks or perhaps claw marks, although this explanation raises doubts.

A puzzling aspect is that the holes are exclusively located in the back of the jaw. If they were indeed bite marks, it would be expected to find corresponding holes at the front of the jaw as well. Additionally, the pattern of the holes is not consistent with what would be anticipated from a row of teeth, even if the teeth varied in height. Instead, the holes appear to be randomly scattered throughout the jawbone.

These perplexing characteristics challenge the notion of bite marks as the source of the holes, leaving the scientific community to explore alternative explanations.

The team’s hypothesis proposes that the claw marks found in Sue’s jaw could be attributed to courtship behavior, suggesting a unique explanation for the enigmatic holes.

However, with bite and claw marks seemingly unlikely causes, numerous other possibilities remain open to explain the origin of the holes. Dr. O’Connor expressed a willingness to explore these alternative explanations, acknowledging that there may be yet undiscovered possibilities waiting to be considered. She is eager to contribute to the ongoing investigation and unravel the mystery surrounding Sue’s jaw.

Driven by her fascination with paleontology and the thrill of solving mysteries, Dr. O’Connor’s interest in understanding the peculiar jaw holes continues to grow.