Doryaspis

Name: Doryaspis ‭(‬Dart shield‭)‬.
Phonetic: Do-re-ass-piss.
Named By: White‭ ‬-‭ ‬1935.
Classification: Chordata,‭ ‬Agnatha,‭ ‬Heterostraci,‭ ‬Pteraspidiformes,‭ ‬Doraspididae.
Species: D.‭ ‬nathorsti‭ (‬type‭)‬,‭ ‬D.‭ ‬arctica.
Diet: Uncertain.
Size: About‭ ‬15‭ ‬centimetres long.
Known locations: Spitsbergen‭ ‬-‭ ‬Wood Bay Formation.
Time period: Early Devonian.
Fossil representation: Individuals to represent‭ ‬2‭ ‬species.

       Doryaspis was a jawless fish that swam in the‭ ‬oceans of the early Devonian,‭ ‬and one that had an unusual body shape.‭ ‬Like others,‭ ‬it had a rounded box-like body with a long flexible tail,‭ ‬but it also had a long,‭ ‬thin pointed snout projecting from the front,‭ ‬as well as two more thin spike-like projections projecting from the sides of the back of the main body at near right angles from the forward snout,‭ ‬while also being curved slightly forward.
       The function of these three spikes is uncertain,‭ ‬but the rear spikes that pointed to the sides may have acted like hydroplanes to help maintain level swimming.‭ ‬The front spike may have been used to stir up soft sediment to expose small invertebrates and morsels of organic matter that could then be sucked into the jawless mouth.‭
       These spikes of Doryaspis have long been noted as being serrated,‭ ‬but the discovery and naming of a new species has brought the realisation that not all Doryaspis‭ ‬had serrated spikes.‭ ‬The spikes of D.‭ ‬arctica are noted as being smooth,‭ ‬which means the serrated snout and spikes of the type species D.‭ ‬nathorsti are either for inter species recognition,‭ ‬or a feature of a more specialised lifestyle.

Further reading
-‭ ‬THE GENUS DORYASPIS WHITE‭ (‬HETEROSTRACI‭) ‬FROM THE LOWER DEVONIAN OF VESTSPITSBERGEN,‭ ‬SVALBARD,‭ ‬V.‭ ‬I.‭ ‬N.‭ ‬C.‭ ‬E.‭ ‬NT NOEL.‭ ‬PERNÈGRE,‭ ‬2001.



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