Name Meaning: Jurassic Tyrant

her latest blog Geologic Era: Late Jurassic

Vérifiez-le Location Found: Weymouth Harbor (dredge)

important source Estimated Range: England, possibly continental Europe

Size: Roughly 6 meters long

Extinction: Roughly 149 million years ago

Seen below is the partial proximal humerus of a subadult Juratyrant. This bone was dredged off Weymouth Harbor in England, along what is now called the Jurassic coast. Considering the heavy equipment involved in dredging, it is impressive to me that this bone is in as good condition as it is. Many bones that result from dredging appear as if they lost an argument with an ATV.

This bone has a special place in my collection, because it comes from what was essentially a teenage Juratyrant. The roughened surface seen below is where the epiphyseal, or growth plate, would have been. I suspected that it was a cartilage remnant, as the surface resembled the one piece of fossil cartilage I have in the museum. Since the growth plate was made of cartilage, it did not fossilize, but rather rotted away. The fact that the plate was still present means that the animal was not finished growing. It is not uncommon even in this era for predators to die before they reach maturity. This suspicion was confirmed by the paleontologist who supplied me with this specimen.

View showing epiphyseal surface

Juratyrant may have been on the smaller side for a predator, but it was actually an early tyrannosaur. Tyrannosaurs spent most of their evolutionary history relatively small, only attaining truly impressive sizes toward the end of the Cretaceous period. In Juratyrant’s time, they would have been far from the apex predators the would become millions of years later. Juratyrant would have shared its environment with sauropods, stegosaurs, and ornithopods. Overall, the fauna of the Jurassic coast of England would be somewhat similar to that found in the Morrison Formation of the United States.

Image Credits:

Life Restoration: By Nobu Tamura – Own work, CC BY-SA 3.0,