Armored worms come to life in digital 3D models
In his “Allegory of the Cave”, Plato describes a group of people chained to the wall of a cave, observing the world only through the flickering shadows it casts. It provides observers with an incomplete picture of the world, which is two-dimensional and requires speculation.
This is the kind of vision we have of the deep past. Paleontologists are tasked with constructing a picture of Earth’s history from the fine fossilized shadows it leaves behind. These fossil remains of extinct organisms give us a little glimpse of animals that lived and died long before humans arrived. But these preserved tissues, often incomplete, provide an image that is necessarily only part of the truth. A thin shadow of what they really were, leaving us to fill in the gaps with inference and educated speculation.
However, technological advancements coupled with particularly well-preserved specimens allow scientists to leave the proverbial cave and have a clearer picture. A recent study by Dr Sarah M. Jacquet of the Department of Geological Sciences at the University of Missouri and her colleagues used micro-scanners to create models of extinct armored worms – known as Machaeridians – in stunning 3D. Their findings were published in the journal Papers in paleontology.
“CT scans take thousands of x-rays that represent cross-sections through the sample. Then, we imported the images into 3D software to manually highlight the features that interest us on each image. Once we have highlighted each plate, we can create the virtual 3D model, ”Jacquet told SYFY WIRE.
Jacquet was first turned towards the Machéridiens by their advisor during their doctoral project. Some of the specimens used in this work were originally described by Dr. Brian Johnson in 1981. They are found in limestone blocks and are isolated using a weak acid, not stronger than vinegar, which dissolves the limestone leaving the silicate fossils behind. Jacquet scanned hundreds of boxes, most of which contained individual disarticulated plaques, in search of complete animals.
Articulated specimens are extremely rare. Of those hundreds of boxes, Jacquet found only three new fossils of articulated armored worms to add to Johnson’s earlier work.
“We were fortunate that these worms were kept as they are, after being replaced by silica. For this reason, we were able to scan the fossils using a specialized scanner, one at the University of Sydney and one at the University of Missouri. Once we had the scan, it was a matter of putting those X-ray projections into 3D software to create the virtual relocation of the specimens.
The specimens they used were remarkably complete, but had the advantage of being complemented by loose induvial plates which provided additional context for the overall models. The team were able to build models that showed how the plates fit together along the body, providing protection against attack.
Most modern worms avoid attacks by burying themselves in the ground, but these external structures provide additional protection against predators.
“They are almost like the underwater equivalent of the spice worms of Duneexcept on a much smaller scale, ”said Jacquet. “Based on the plate layout for the species we observed, assembling the armor was likely an effective deterrent against crushing, biting, and piercing predatory attacks. “
The body shots of these armored worms closely resemble modern animals like centipedes, bedbugs, and pangolins that curl up into protective balls to avoid being eaten, although this type of strategy was rare at the time. . Similar structures are present in unrelated modern organisms, suggesting that converging evolutionary processes have developed independent body planes to combat similar predatory challenges.
Now that scientists have clear 3D models of these animals, they are looking to develop images of their movements to better understand how they navigated ancient ocean environments.
“We want to explore how the rows of plates fit together and how the armor responds to different types of stress, which might tell us more about its effectiveness in protecting these worms from certain predators,” Jacquet said.
Modern technologies allow us to take disparate, unconnected pieces of the fossil record and place them together in context to build a stronger picture. Additionally, 3D modeling enables the dissection of individual specimens – which previously required the destruction of fossils – unlocking internal mechanisms and interrelationships.
Ancient animals recovered from subterranean sediments find their way not only to the surface, but also into virtual spaces where scientists are able to translate them from individual puzzle pieces into 3D organisms that more closely mirror the animals than they do. were once.
While jurassic park imagining prehistoric resurrections via genetic manipulation, real-world scientists are bringing ancient animals back to life in digital spaces. Your ticket to prehistoric lands may not exist in the reconstructed real world, but in virtual landscapes populated by armored underground worms.
At least digital animals can’t eat us alive when we visit them.