Halwaxiida - Ecology

Ecology

Halwaxiid sclerites were not able to grow once they had been formed, but must rather have been either moulted or resorbed to make way for new, larger sclerites; the smallest Wiwaxia specimens, 3.4 mm in length, appear to bear the same number of sclerites (minus the spines) as adults 5 cm long. The new sclerites cannot simply have poked between existing sclerites; rather they must have been shed or resorbed, either one at a time or all at once; presumably the latter, as the close-fitting nature of the armour does not seem compatible with the easy loss of individual sclerites.