Jellyfish are among the most ancient and diverse animals on Earth. They belong to a group of aquatic invertebrates called medusozoans, which also includes box jellies, hydroids, and stalked jellyfish. Medusozoans are characterized by having a gelatinous body with tentacles and stinging cells.
They are also part of a larger group of animals called cnidarians, which also includes corals and sea anemones.
Cnidarians are thought to have evolved more than 500 million years ago, making them one of the oldest groups of animals to have existed.
However, the fossil record of jellyfish and their relatives is very scarce and incomplete, as they are mostly composed of water and decay quickly after death.
Therefore, finding and identifying ancient jellyfish fossils is a challenging and exciting task for paleontologists.
A new species of swimming jellyfish from the Cambrian period
RONALDO SCHEMIDT/AFP via Getty Images
A recent study by researchers from the Royal Ontario Museum (ROM) in Canada has announced the discovery of a new species of swimming jellyfish from the Cambrian period, about 505 million years ago.
The study was published in the journal Proceedings of the Royal Society B, as per Phys.org.
The new species, named Burgessomedusa phasmiformis, was identified from rare fossil specimens collected from the Burgess Shale in British Columbia, Canada.
The Burgess Shale is one of the most famous and important fossil sites in the world, as it preserves exceptional details of soft-bodied animals that lived in the Cambrian sea.
Burgessomedusa phasmiformis is the oldest known species of swimming jellyfish in the fossil record.
It had a saucer- or bell-shaped body that could reach up to 20 centimeters in height, with about 90 short tentacles that it used to capture prey.
The fossils showed remarkable preservation of internal anatomy and tentacles, which enabled the researchers to classify Burgessomedusa as a medusozoan.
By comparing it with modern jellyfish, the researchers also inferred that Burgessomedusa was capable of free-swimming and had a powerful voice that could be heard over long distances.
The significance and implications of the discovery
The discovery of Burgessomedusa phasmiformis has several implications for our understanding of the evolution and diversity of jellyfish and their relatives, as per The Guardian.
First, it confirmed that large, swimming jellyfish with a typical body plan had already evolved more than 500 million years ago, during the Cambrian explosion, when most major animal groups appeared.
Second, it also showed that jellyfish were efficient predators that played an important role in the Cambrian food web, alongside other famous creatures such as Anomalocaris.
Third, it revealee that jellyfish have a long and complex evolutionary history that is still poorly understood and requires more research and exploration.
The discovery of Burgessomedusa phasmiformis also has implications for our appreciation and conservation of jellyfish and their relatives.
Jellyfish are often regarded as pests or nuisances by humans, as they can cause problems, such as stinging swimmers, clogging fishing nets, or damaging power plants.
However, they are also fascinating and valuable organisms that deserve our respect and care. Jellyfish are vital for the functioning and balance of marine ecosystems, as they provide food and habitat for many other animals.
They are also indicators of environmental change, as they respond quickly to changes in temperature, salinity, oxygen, or pollution.
Jellyfish are also sources of inspiration and innovation for science and technology, as they have unique properties, such as bioluminescence, regeneration, or symbiosis.
