The majority of fossils discovered by scientists are preserved in sedimentary rocks, where layers of minerals cover the organism and over centuries turn them into stone. However, the stunning golden fossils recently found in New York state are somewhat different, as reported by Science Alert.
According to paleobiologist Luke Perry from Oxford University, the recently uncovered remains were slowly replaced by a metal known as iron pyrite, or "fool's gold," which ensured their preservation for 450 million years.
The remarkable golden hue is not the only feature of these remains; these fossils are also incredibly well preserved. But that's not all. Researchers have also discovered that the recently found remains belong to a previously unknown species.
The new species has been named Lomankus edgecombei and represents a marine creature belonging to an extinct class of arthropods with large grasping appendages located at the front of the body — the Megacheirans.
It is worth noting that the fossilization process can be quite harsh on the original material. Often, this process subjects the remains to pressure, heating, or a combination of both, leading to deformation of the anatomy. As a result, scientists often find it challenging to examine the features of the animal in three dimensions.
In the new study, Perry and colleagues examined a fossil layer containing fossils of various ancient trilobites, whose bodies had transformed into "fool's gold" over time. The researchers believe that the animals were buried alive in massive sediment piles, transported by phenomena known as turbidity currents. This created a unique set of conditions that allowed the ancient arthropods to pyritize from the outside in.
As a result, the fossils of the new species are exceptionally well preserved and easy to study in three dimensions — providing scientists with new insights into the anatomy of the megacheirans. The researchers point out that these tiny creatures are particularly intriguing as they lived during a time when megacheirans were in decline. It is important to note that during the Cambrian period, this class of creatures was numerous and widespread, but mostly went extinct by the onset of the Ordovician period, between 485 and 443 million years ago.
In simple terms, the found fossils of L. edgecombei likely belong to one of the last surviving species of Megacheiran on Earth. The team also managed to study the anatomy of the new species, indicating that the appendages on the heads of the arthropods seem to have transformed into antennae, claws, and fangs that can be observed today in insects, crustaceans, and arachnids.
Perry notes that today arthropods are one of the most diverse groups of animals on Earth. It is suggested that part of this success lies in the adaptation of their heads and appendages to various challenges.
The new fossils also indicate that the grasping appendages, which are present in other species of Megacheirans, have reduced in size and changed shape, suggesting a change in function. Scientists found that the claw used for grasping in other species is significantly smaller. At the same time, three long, whip-like appendages known as flagella are much longer. The new species also lacked eyes, indicating that they used their appendages for spatial orientation rather than for capturing prey.