April 3, 2015
Ancient seashells were way cooler than modern ones
Thirteen newly-discovered species of seashells show that they haven’t always been dull white, and at one time even featured a vast array of different distinctive colors and patterns, according to research published Wednesday in the journal PLOS One.
In the study, Jonathan Hendricks from San Jose State University in California uncovered a total of 30 ancient seashell species coloration patterns by placing them under ultraviolet light, which causes the organic matter remaining in the shell to become fluorescent. The UV light reveals the original coloration patterns of the shells, which had at one time been living creatures.
Back in the good ol' days
It is uncertain exactly what compounds in the matrix of the shells are emitting light once exposed to UV rays, but by using this technique, Hendricks was able to view the coloration patterns of 28 different cone shell species from the Dominican Republic, including 13 which appear to be new creatures.
The fossils came from the from the Cibao Valley region of the northern Dominican Republic and range in age from approximately 6.6 to 4.8 million years old. When the ancient cone snail shells were compared to modern Caribbean shells, remarkable similarities were found, suggesting modern snails belong to a lineage that has survived for millions of years.
While the classification of the new species has not yet been fully completed, Hendricks said that they had been “assigned to three genera of cone snails (Profundiconus, Conasprella, and Conus) and at least nine subgenera.” One of the most striking creatures he discovered was a shell that was covered with large polka dots – a feature that is largely extinct among modern cone snails.
Still more questions to be answered
Hendricks has listed the new species as follows (using question marks indicate ongoing research on the species’ phylogeny): Profundiconus? hennigi, Conasprella (Ximeniconus) ageri, Conus anningae, Conus lyelli, Conus (Atlanticonus?) franklinae, Conus (Stephanoconus) gouldi, Conus (Stephanoconus) bellacoensis, Conus (Ductoconus) cashi, Conus (Dauciconus) garrisoni, Conus (Dauciconus?) zambaensis, Conus (Spuriconus?) kaesleri, Conus (Spuriconus?) lombardii, and Conus (Lautoconus?) carlottae.
While some of the creatures, including the polka-dotted one, have long gone extinct, others continued to evolve slowly over the years, according to Discovery News. Hendricks believes that each of the three coral reef deposits where he found the shells contained at least 14 to 16 different types of cone snails, putting their biodiversity levels on part with today’s Indo-Pacific reef systems.
However, there is still a mystery surrounding the shells, he told the website: “While the use of UV light to reveal ancient shell coloration patterns has proved to be a useful technique for understanding the systematics of some fossil mollusks, we still do not have a clear understanding of exactly what compounds are responsible for pigmentation in modern shells, much less what matter is actually fluorescing in the fossil shells.”