from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Having three germ layers. Used of the vertebrate embryo.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Exhibiting triploblasty.
from the GNU version of the Collaborative International Dictionary of English
- adj. Of, pertaining to, or designating, that condition of the ovum in which there are three primary germinal layers, or in which the blastoderm splits into three layers.
from The Century Dictionary and Cyclopedia
- Having three blastodermic membranes or germ-layers, consisting of epiblast, mesoblast, and hypoblast; of or pertaining to the Triploblastica: distinguished from diploblastic as cœlomatous from cœlenterate. Most animals are triploblastic.
While bilaterality is a defining characteristic of triploblastic animals, several assemblages have managed to break this symmetry in order to exploit the adaptive peaks garnered through the lateralization of behaviour or morphology.
"The essence of all these propositions," he writes, "lies in the fact that the segmented animals are traced back not to a triploblastic unsegmented ancestor, but to a two-layered Coelenterate-like animal with