Final answer:
The new body form that contributed to the Cambrian Explosion was characterized by multicellularity, leading to a diversity of complex organisms. Major factors that might have caused the Cambrian Explosion include environmental changes, habitat expansion, and genetic and developmental innovations.
Step-by-step explanation:
The type of body form that was a relatively new development and that enhanced the Cambrian Explosion was multicellularity, which gave rise to a diversity of complex organisms. During the Cambrian period, there was a significant increase in animal diversity with the emergence of many animal phyla that are still in existence today. Two examples of the marine life that thrived during this time are the sponge and the trilobite, both of which were abundant but are now extinct.
The Cambrian explosion may have been caused by a variety of factors. One theory centers on environmental changes like rising atmospheric oxygen levels and increased oceanic calcium concentrations, which may have supported more complex forms of life. Another theory suggests that increased space for habitats, such as shallow lagoons on continental shelves, allowed for greater diversification. Additionally, ecological changes in predator-prey relationships, competition for resources, and coevolution of species could have fueled this rapid diversification. Last but not least, genetic and developmental innovations such as the evolution of Hox control genes likely provided the morphological flexibility needed for the explosion of animal forms during this era.