New species of meat-eating dinosaur that once roamed South Wales: an imaging technology revolution

Imaging technology has revolutionized paleontology, allowing scientists to study fossils that are buried deep in rock or too shallow to handle. Two recent studies I was involved in showed some of the technology’s potential, including a new dinosaur species that evolved over other carnivores that lived alongside it hundreds of millions of years ago.

In the first study, my colleagues and I investigated a fossil jawbone impression that was described in 1899 as coming from only one possible dinosaur. Because of its age (203 million years), the specimen had increased significance as, possibly, an unusually large meat-eating dinosaur.

Dinosaurs began to appear during the Triassic period, 252–201 million years ago, but typically the meat-eating forms lived up to 3 meters in length and weighed no more than an Alsatian dog. We knew the 1899 specimen, from the Late Triassic near Cardiff in South Wales, showed the jaws and parts of carnivorous teeth of an ancient animal, and they could have come from an animal five meters or more in length.

Since 1899, this specimen has not been studied much because it only included impressions in the rock. At the time of discovery, the block was split open, revealing the inside and outside impression of the mandible, which contained 16 teeth and tooth sockets. But the original bone material did not survive.

Traditionally, paleontologists make casts of the specimen using plaster or some flexible plastic, but such casting can damage the delicate fossil. So the specimen remained in storage in the museum for over a century.

We used a new but simple method to obtain 3D models called photogrammetry. It involves taking multiple photos of two natural rock formations and then stitching them together using 3D modeling software, much like the panorama function on many smartphones that can stitch images of a wide vista.

The resulting 3D jaw can be viewed from all sides and rotated. This makes it easier to study than stone molds.

This procedure does not damage the unique fossil specimen and can be shared with other scientists for further examination. In this case, the natural rock mold was highly detailed, retaining information about the canals through the bone for blood vessels and nerves, and even serrations on the cutting edges of the teeth.

We compared it to other dinosaur fossils and determined that it came from a dinosaur from the Early Jurassic period, 201-174 million years ago, in the Americas. But it was 10 million years older and an entirely new genus and species.

We named it Newtonsaurus cambrinus after Edwin Tilley Newton, who first studied it in 1899. Jaws originally suggested a 5-7 meter long, bipedal carnivorous animal with hands and powerful jaws.

In another study, we also scanned a small reptile skeleton from Triassic rocks. It was found in Devon and was 40 million years old at 243 million years old.

When it was found in 2015, the collector, Rob Coram, tried to clean the tiny skeleton using traditional methods, removing grains of sand with a fine needle. However, the small size of the specimen, with a skull of 1 cm and three teeth per millimeter, made this impossible.

We first scanned CTX-rays on a regular microCT scanner and performed detailed 3D reconstructions. The detail wasn’t enough, though, so we then scanned it at the European Synchrotron in Grenoble, France, so every tooth, and many other structures, could be rendered in detail. A synchrotron creates an extremely intense beam of light that scientists use to study minute matter.

Scans and reconstructions tell us that this tiny reptile, which we named Agrodontosaurus, was an insect eater. He made out with cockroach-like bugs as big as his head and crushed their cuticles with chisel-like teeth.

Virtual Paleontology

With hundreds of scanning machines installed in university and museum research departments, CT scanning has become ubiquitous in paleontology.

In the case of Agridontosaurus, CT scans gave us clear views of the compact and less compact bone as well as the zones of tooth attachment.

Now 3D digital models let scientists see inside bones and shells, revealing hidden anatomical information. For example, many shell organisms, such as ammonites and foraminifera, evolved from a single shell chamber throughout their lives, ever pointing outwards as they lay down new living chambers. The entire developmental history is contained within the adult shell and can be distinguished in scans.

Digital models of fossils can also be used for functional experiments. For example, the mechanical properties of the skull can be analyzed, modeling where an animal’s jaw and skull attach, reconstructing its muscles and calculating its bite forces. This tells us that Tyrannosaurus rex could use a bite force of 50,000 newtons, equivalent to a force of 5 tons.

Another approach, finite element analysis, allows pathologists to examine the response of the skeleton or skull to compression and tension. For example, these bioengineering studies have shown that predatory dinosaurs were generally not good at grappling with their prey by twisting and turning—they mainly focused on straight up and down cuts.

This is the new world of virtual paleontology. Let’s see where this takes us.

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