Marrella

Name: Marrella.
Phonetic: Mar-rel-lah.
Named By: Charles Doolittle Walcott‭ ‬-‭ ‬1912.
Classification: Arthropoda,‭ ‬Marrellomorpha,‭ ‬Marrellida,‭ ‬Marrellidae.
Species: M.‭ ‬splendens‭ (‬type‭)‬.
Diet: Detritivore.
Size: About‭ ‬2‭ ‬centimetres long.
Known locations: Canada,‭ ‬British Columbia‭ ‬-‭ ‬Burgess Shale.
Time period: Mid Cambrian.
Fossil representation: Over‭ ‬25,000‭ ‬individuals have been recorded.

       The genus Marrella has the distinction of being the most common animal found in the world famous Burgess Shale.‭ ‬When first described in‭ ‬1912‭ ‬Marrella was thought to possibly be a lace crab,‭ ‬and then later a trilobite.‭ ‬Later studies have now concluded however that Marrella is actually a stem arthropod,‭ ‬related to the ancestors of true arthropods,‭ ‬yet not necessarily an ancestor itself.‭
       Marrella tended to have around twenty-four to twenty-six body segments,‭ ‬and two large pairs of rearward facing spines.‭ ‬The legs of Marrella are interesting in that the upper legs had gills for absorbing oxygen from the water.‭ ‬Some better preserved specimens reveal the presence of a diffraction grating pattern,‭ ‬meaning that in life Marrella would have had an iridescent sheen.‭ ‬All in all Marrella is thought to‭ ‬have been a bottom dweller that sifted through the soft sediment for morsels of organic matter to eat.

Further reading
-‭ ‬Redescription of Marrella splendens‭ (‬Trilobitoidea‭) ‬from the Burgess Shale,‭ ‬Middle Cambrian,‭ ‬British Columbia.‭ ‬-‭ ‬Bulletin‭ – ‬Geological Survey of Canada‭ ‬209‭ ‬-‭ ‬H.‭ ‬B.‭ ‬Whittington‭ ‬-‭ ‬1971.
-‭ ‬Colour in Burgess Shale animals and the effect of light on evolution in the Cambrian.‭ ‬-‭ ‬Proceedings of the Royal Society B:‭ ‬Biological Sciences‭ ‬265‭ (‬1400‭)‬:‭ ‬967‭–‬972.‭ ‬-‭ ‬A.‭ ‬R.‭ ‬Parker‭ ‬-‭ ‬1998.
-‭ ‬Moulting arthropod caught in the act.‭ ‬-‭ ‬Nature‭ ‬429‭ (‬6987‭)‬:‭ ‬40.‭ ‬-‭ ‬D.‭ ‬C.‭ ‬García-Bellido‭ & ‬D.‭ ‬H.‭ ‬Collins‭ ‬-‭ ‬2004.



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