What do the elements in the Aztec day signs represent?

Clearly several of the signs are self-explanatory:Cuetzpalin (‘Lizard’), Coatl (‘Serpent’ - it’s a rattlesnake), Mazatl (‘Deer’), Tochtli (‘Rabbit’), Itzcuintli (‘Dog’), Ocelotl (‘Jaguar’), Cuauhtli (‘Eagle’), Xochitl (‘Flower’. For the others Professor Whittaker has offered the following most helpful pointers:-

• Cipactli (‘Crocodilian’, ‘Dragon’, sometimes ‘Alligator’...): the red items projecting upwards from the snout are knives, symbolizing sharp horns, while the smaller grey extensions depict the rough scales lining the body of the beast
• Ecatl/Ehecatl (‘Wind’): the bird-like head, with its red nostril projection, represents the god Quetzalcoatl, wearing his characteristic orange-brown head ornament, in his guise as the wind
• Calli (‘House’): a temple façade in profile
• Miquiztli (‘Death’): a death’s head with red ornamention over the nose area, symbolizing blood
• Atl (‘Water’): a stream rushing forwards along its course, flanked by white shell.

• Ozomatli (‘Monkey’): a spider monkey with the ear ornament relating it to Quetzalcoatl
• Malinalli (‘Grass’): a type of wild grass associated with death and regrowth, hence the death’s head from which it sprouts
• Acatl (‘Reed’): a reed plant, the central shaft of which is a white-feathered, reed arrow
• Cozcacuauhtli (‘Vulture’): a vulture with the ear ornament of Quetzalcoatl
• Olin (‘Movement’): a symbol perhaps of twirling throwsticks, with an eye representing the central pivot
• Tecpatl (‘Flint’): a flintstone knife, with eye and teeth, representing the bite of the sacrificial knife
• Quiahuitl (‘Rain’): the head of the god of rain and storms, Tlaloc.

Day sign illustrations drawn specially for Mexicolore by Felipe Dávalos ©Mexicolore.