 
 <prompt> Which time period happen second, the early Ordovician or the end of the Carboniferous? Given the previous question, write a context wey contain the answer. E fit be 1 - 20 sentences. Context: <response>: Since annelids dey soft-bodied, dem fossils dey rare. Polychaetes' fossil record na mainly di jaws wey some species get and di mineralized tubes wey some secrete. Some Ediacaran fossils like Dickinsonia somehow resemble polychaetes, but di similarities dey too vague for dem fossils to dey classified with confidence. Di small shelly fossil Cloudina, wey dey from 549 to 542 million years ago, some authors don classify am as an annelid, but others classify am as a cnidarian (i.e. for di phylum wey jellyfish and sea anemones dey belong). Until 2008 di earliest fossils wey people widely accept as annelids na di polychaetes Canadia and Burgessochaeta, both from Canada's Burgess Shale, wey form about 505 million years ago for di early Cambrian. Myoscolex, wey dem find for Australia and e small pass Burgess Shale, fit be an annelid. However, e no get some typical annelid features and get features wey no dey usually find for annelids and some wey dey associated with other phyla. Then Simon Conway Morris and John Peel report Phragmochaeta from Sirius Passet, wey dey about 518 million years old, and dem conclude say e na di oldest annelid wey people sabi so far. People don dey argue well well whether di Burgess Shale fossil Wiwaxia na mollusc or annelid. Polychaetes diversify for di early Ordovician, about 488 to 474 million years ago. E no reach di early Ordovician before people find di first annelid jaws, so di crown-group no fit don appear before dis time and e fit don appear small small later. By di end of di Carboniferous, about 299 million years ago, fossils of most of di modern mobile polychaete groups don appear. Many fossil tubes dey look like those wey modern sessile polychaetes dey make, but di first tubes wey clearly produce by polychaetes na from di Jurassic, wey dey less than 199 million years ago. 