Description

Hurdia, an extinct hurdiid radiodont genus, thrived approximately 505 million years ago during the Cambrian Period. Its fossils have been unearthed in various locations including North America, China, and the Czech Republic. Hurdia stood out as one of the largest organisms inhabiting the Cambrian oceans. Its head featured a pair of frontal appendages, which possessed either 9 segments, and more rarely 10 or 11, arranged in an approximately rectangular shape that tapered towards the tip. These appendages displayed a gently curved upper surface.

The primary function of these frontal appendages was to transport food to its mouth, which took the form of a ring-shaped oral cone. Inside this oral cone, four large plates were present, accompanied by inner rows of spines. Hurdia's use of its frontal appendages is subject to debate, with some suggesting that they were employed for sifting small prey from sediment, while others propose that they served as a mechanism to capture larger benthic (seafloor-dwelling) prey.