Each segment has the same sets of organs and, in most polychaetes, has a pair of parapodia that many species use for locomotion. Septa separate the segments of many species, but are poorly defined or absent in others, and Echiura and Sipuncula show no obvious signs of segmentation.ach segment has the same sets of organs and, in most polychaetes, has a pair of parapodia that many species use for locomotion. Septa separate the segments of many species, but are poorly defined or absent in others, and Echiura and Sipuncula show no obvious signs of segmentation.
Chicxulub is most famous for being near the geographic center of the Chicxulub crater, an impact crater discovered by geologists on the YucatÃ¡n Peninsula and extending into the ocean. It was created by the impact some 65 million years ago of the Chicxulub impactor, an asteroid or comet which caused the CretaceousâPaleogene extinction event, which led to the demise of the dinosaurs.
The Yucatan YucatÃ¡n (Peninsula: Spanish peninsula PenÃ­nsula), de yucatan YucatÃ¡n, in southeastern Mexico Separates the caribbean Sea from The, gulf of mexico with the northern Coastline On. the yucatan yucatÃ¡n channelince the 1970s (and the fall of the world henequen and chicle markets due to the advent of synthetic substitutes), the Yucatan YucatÃ¡n peninsula has reoriented its economy towards, tourism especially in The mexican state Of Quintana. roo