Giant Cambrian shrimp fossils discovered in Northern Greenland

Both Tamisocaris and its cousin had compound eyes that would later be a defining characteristic of many insects, and also a circular mouth.

 

Science Recorder | James Sullivan | Thursday, March 27, 2014

On Wednesday, paleontologists announced the discovery of a strange sea creature that swam the oceans over 520 million years ago, during the Cambrian explosion, when a stunning array of diversity first appeared on the Earth. The newly discovered creature, a small filter feeding arthropod called Tamisocaris, reached 28 inches long. It is a distant cousin of the famous Anomalocaris, which may have been one of the world’s oldest apex predators, and whose modern day descendants include centipedes.  Although both the Tamisocaris and Anomalocaris are both members of the classification group that includes crustaceans, insects, and arachnids, nothing quite like the Tamisocaris, which was first found in a Greenland shale bed back in 2009, is alive today.
According to the leader of the study, paleontologist Jakob Vinther from Britain’s University of Bristol, the Tamisocaris was one of the largest creatures alive in the Cambrian, making it what Vinther referred to as a “gentle giant.” Although it’s not the same as a whale or a basking shark, it filled a similar ecological role at the time – using comb-like bristles on its appendages to trap bits of plankton and zooplankton – small plants and animals that it would eat, sucking the pieces into its mouth, rather than hunting and stalking prey.
The Anomalocaris possessed a similar pair of spiny, grasping appendages by its mouth, but with the purpose of catching prey, such as trilobites and small jawless fish. Both Tamisocaris and its cousin had compound eyes that would later be a defining characteristic of many insects, and also a circular mouth.  Although legless, it had a number of flaps down its back that made swimming movements possible.
What is significant is that the adaptation of filter feeding may suggest insights into how the similar development happened in whales, which are also plankton feeders, as well as crustaceans, some of which grow fairly large but feed primarily with spiny appendages like Tamilocaris. Both animals lived alongside primitive shellfish, jellyfish, and starfish, as well as jawless fish and a diverse array of trilobites, but the existence of Tamilocaris suggests a greater deal of diversity may have existed among arthropods than was previously thought and that the Cambrian age was home to a number of species that have yet to be discovered.

Source: http://www.sciencerecorder.com