from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. In front of the notochord
from The Century Dictionary and Cyclopedia
- Situated in front of the notochord: applied to those parts of the brain which are anterior to the end of the chorda dorsalis: correlated with epichordal and parachordal.
- Prior in time to the existence of the Chordata or chor-date animals; before the evolution of a notochord in animals.
Sorry, no etymologies found.
Recent observations have shown that, in mammals, the basi-cranial cartilage, both in the chordal and prechordal regions of the base of the skull, is developed as a single plate which extends from behind forward.
In the lower vertebrates two pairs of cartilages are developed, viz., a pair of parachordal cartilages, one on either side of the notochord; and a pair of prechordal cartilages, the trabeculæ cranii, in front of the notochord (Fig. 66).
The base of the skull may therefore be divided into (a) a chordal or vertebral, and (b) a prechordal or prevertebral portion.