When fossils of an extinct creature are discovered, one of the first steps to understanding them is finding the modern equivalent of the animal. Still, this can be quite difficult sometimes due to lack of information about the ancient animal. Scientists were particularly baffled by a strange cone shaped creature that was first found years ago After 175 years, hyoliths have finally found a proper placement within the animal kingdom.
Strangely Shaped Marine Animal Is Finally Classified in Evolutionary Tree
For over a century, scientists were confused by the discovery of fossils that were shaped like cones. The fossils were found all throughout geographic locations and time period, and they had apparently first evolved during the Cambrian explosion. They survived for almost 250 million years before going extinct.
These fossils were not even named until 1963 because it was hard for scientists to tell if they were a unique species. or not, let alone where would they fit in the evolutionary tree. Even after they were named, the hyolith fossils’ unique shape still continued to be a source of debate. Most specimens were broken or badly preserved, so it was difficult to determine if a fossil was a hyolith or just a similarly shaped animal.
A hyolith closely resembles an ice cream cone because one end is sharply pointed and the other is gently rounded. The cone shaped creatures tend to be just a few centimeters long. They had a tough outer shell that protected most of the interior, and it was topped with a smaller shell that acted like a type of cap across the opening.
Typical fossils of hyoliths just contained their shell, without any soft tissue, so it was hard for scientists to classify them. Some scientists thought that hyoliths were a sort of squid because their cone shape looked somewhat squid-like, and others argued that hyoliths were a type of snail. The only thing that scientists were certain about was when and where the hyoliths lived.
This lack of information changed in 2017 when researchers at the University of Toronto were able to examine over 1,500 well preserved hyolith specimens from the British Columbia fossil site at Burgess Shale. They found that the hyoliths had a ring of ciliated tentacles around their top opening and two long tapered structures that extended from either side of the small tentacle ring.
The recent discoveries provided enough insight to classify hyoliths as a part of the Lophophorata group. Lophophorates include both extinct species like hederelloids and living species like brachiopods. These animals tend to be small marine creatures with a tough shell that opens to show feeding tentacles that are called “lophophores.”
Scientists now theorize that hyoliths were able to live for so long in many different locations due to this clever feeding mechanism. They could use the pair of tapered structures, named “helens” to push their body out of the sand and detritus on the ocean floor. After pointing their openings into the ocean current, the hyoliths could then use their tentacles to filter tiny bits of organic material out of the water and push the food into their shell opening.
New Understandings Benefit Scientific Community
Any new information about hyoliths and its place in the evolutionary tree helps scientists to learn more about the history of the planet. The hyoliths are now part of the Lophophorata group that are aquatic animals with a ring of tentacles in the mouth. This new classification may help scientists to understand why hyoliths went extinct and prevent their modern relations from also going extinct later on. Lophophorata play an important role in the marine ecosystem, so their presence is extremely useful.
Photo by Pseudorhina @DeviantArt