20200410 Radiodonta Cambroraster falcatus head

''Cambroraster'' is an extinct monotypic

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of hurdiid

radiodont Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. They may be referred to as radiodonts, radiodontans, radiodontids, anomalocarids, or anomalocaridids, although the last two original ...

, dating to the middle Cambrian, and represented by the single formally described species ''Cambroraster falcatus''. Hundreds of specimens were found in the

Burgess Shale The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. It is famous for the exceptional preservation of the soft parts of its fossils. At old (middle Cambrian), it is one of the earliest fo ...

, and described in 2019. A large animal (for its era) at up to 30cm long (but not as long as '' Titanokorys'' at 50 cm), it is characterized by a significantly enlarged horseshoe-shaped dorsal carapace (H-element), and presumably fed by sifting through the sediment with its well-developed tooth plates ( oral cone) and short frontal appendages with hooked spines. It is named partially after the fictional

Millennium Falcon The ''Millennium Falcon'' is a fictional starship in the '' Star Wars'' franchise. Designed by Joe Johnston for the movie '' Star Wars'' (1977), it has subsequently appeared in '' The Star Wars Holiday Special'' (1978), ''The Empire Strikes Ba ...

, which its dorsal carapace resembles. File:20200329 Cambroraster falcatus.png, Reconstruction File:20210516 Radiodonta head sclerites Cambroraster falcatus.png, Head sclerites File:20191229 Radiodonta frontal appendage Cambroraster falcatus.png, Frontal appendage File:20210813 Cambroraster falcatus frontal appendage mobility.gif, Movement range of the frontal appendage A second species of ''Cambroraster'' is known from the

Chengjiang Biota The Maotianshan Shales are a series of Early Cambrian deposits in the Chiungchussu Formation, famous for their '' Konservat Lagerstätten'', deposits known for the exceptional preservation of fossilized organisms or traces. The Maotianshan Shales ...

of South China, making it the first uncontroversial hurdiid from the Cambrian of China. This species is known only from a juvenile dorsal carapace, so it was not given a specific name. Although originally suggested to have used its frontal appendages to sift sediment for prey, a later study by different authors suggested that it may have been a

filter feeder Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...

instead.

References

{{Taxonbar, from=Q66108229 Cambrian arthropods Burgess Shale fossils Fossil taxa described in 2019 Cambrian genus extinctions Anomalocaridids