Naraoia

Name: Naraoia (‬Narao‭ ‬-‭ ‬After a group of lakes in British Columbia near where the first specimens were found).
Phonetic: Na-ray-oy-a.
Named By: Charles Doolittle Walcott‭ ‬-‭ ‬1912.
Classification: Arthropoda,‭ ‬Chelicerata,‭ ‬Nektaspida,‭ ‬Naraoiidae.
Species: N.‭ ‬compacta‭ (‬type‭)‬,‭ ‬N.‭ ‬bertiensis,‭ ‬N.‭ ‬spinifer,‭ ‬N.‭ ‬spinosa,‭ ‬N.‭ ‬tianjiangensis.
Diet: Uncertain,‭ ‬may have been either a carnivore or a detritivore.
Size: Around‭ ‬20‭ ‬to‭ ‬45‭ ‬millimetres long.
Known locations: Australia,‭ ‬Canada‭ ‬-‭ ‬Burgess Shale,‭ ‬China and USA.
Time period: Lower Cambrian to Late Silurian.
Fossil representation: Multiple specimens.

       Naraoia is so different to other trilobites that it was actually misidentified as a crustacean until some specimens were dissected by Harry Blackmore Willington.‭ ‬The reason why Naraoia was not immediately identified as a trilobite was because the multiple segments that reveal it to be one were hidden from view by two large shields called the cephalon‭ (‬the forward one over the head‭) ‬and pygidium‭ (‬the one at the back that covers the rear portions of the body.
       Naraoia is noted for having a large digestive tract with width between one sixth and one fifth the width of the body.‭ ‬This broad gut has been interpreted as both being for processing a large amount of sediment‭ (‬for the extraction of organic matter within‭) ‬as well as swallowing prey animals.‭ ‬There are no eyes present to suggest predation,‭ ‬but numerous antennae radiated out from the size,‭ ‬and these might have been used to feel for nearby prey animals.
       Although the body of Naraoia was covered by two large plates,‭ ‬fossil specimens reveal that the joint between these could bend by as much as ninety degrees.‭ ‬Additionally large distal lobes would have been suitable for shifting large quantities of sediment,‭ ‬and their placement along with the other side wards antennae have all been taken as adaptations to a burrowing lifestyle.



----------------------------------------------------------------------------

Random favourites