506 Million-Yr-Old Fossil of a Three-Eyed Moth-Like Sea Predator Discovered, It Breathed Through Its Butt

New fossils of a moth-like creature often help researchers gain new insights regarding the particular species. Mosura fentoni was discovered a long time ago, but a newly analyzed specimen has given some eye-opening details about this predator, according to Live Science. Findings regarding this analysis have been published in the journal Royal Society Open Science. 

The specimen was uncovered from the Burgess Shale rock formation in the Canadian Rockies. For a long time, it was in the custody of the Royal Ontario Museum Invertebrate Palaeontology collections (ROMIP). Recently, it was taken for examination by a team of researchers, who detected some bewildering features that showcase how advanced it was in reality. 

Examinations revealed that the specimen was 506 million years old. The fossil stands apart from others of its kind because it was so well preserved that experts could see the intricate details of the species' biology, such as its digestive tract, nervous system, and circulatory system.

As per the museum, the specimen was found between 1975 and 2022, according to Fox News. "Mosura fentoni was about the size of your index finger and had three eyes, spiny, jointed claws, a circular mouth lined with teeth, and a body with swimming flaps along its sides," the museum noted about the features of this fossil. 

Experts claim that M. Fentoni is a species of arthropod that lived during the Cambrian Period, according to ABC News. This specimen showcases that the creature was more diverse than previously thought. The fossil exhibits that this species had an open circulatory system, which pumped blood inside large internal body cavities called lacunae. This circulatory system could be detected on the fossil as reflective patches. 

The insights from the fossil indicated to researchers that these creatures were efficiently adapting to the conditions around them. One of the most noteworthy parts of this fossil was the creature's rear section. Researchers noted that this section in M. Fentoni was somewhat similar in appearance to modern arthropods like horseshoe crabs and insects. The section was covered with gills and seemed to be divided into multiple segments. "This is a neat example of evolutionary convergence with modern groups, like horseshoe crabs, woodlice, and insects, which share a batch of segments bearing respiratory organs at the rear of the body,” said Joe Moysiuk, curator of paleontology and geology at the Manitoba Museum and lead author of the study. 

Experts think that these gills were used for respiration, according to Live Science. This specialized form of respiration is also found in insects and horseshoe crabs. Researchers believe these gills were used to breathe in low-oxygen environments or for handling an active lifestyle that required a lot of energy. 

This feature had not been observed in any other specimen of the species to date, stated Fox News. Moysiuk claimed that there were 16 segments in total in the rear section. Field collectors over the years have nicknamed the creature 'sea moth' because of its moth-like features. "This inspired its scientific name, which references the fictional Japanese kaiju also known as Mothra. Only distantly related to real moths – as well as spiders, crabs, and millipedes – Mosura belongs on a much deeper branch in the evolutionary tree of these animals, collectively known as arthropods," the museum further said. 

Researchers claimed that M. Fentoni belongs to radiodonts, an extinct group of arthropods. Past studies have showcased that this group was the first one to branch out in the evolutionary tree. Hence, such detailed fossils aid researchers in knowing more about the eventful journey arthropods have been on across centuries.