from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Alongside the notochord in the embryonic skull
- n. Such a bar of cartilage that will form the base of the skull
from the GNU version of the Collaborative International Dictionary of English
- adj. Situated on either side of the notochord; -- applied especially to the cartilaginous rudiments of the skull on each side of the anterior part of the notochord.
from The Century Dictionary and Cyclopedia
- In embryology,lying alongside of the cephalo-chord or cranial part of the notochord: specifically noting the primitive undifferentiated plate of cartilage cartilaginous basis cranii, lying on each side and in front of the notochord of the early embryo, and laying the foundation of the skull. See cut under chondrocranium.
- n. The parachordal plate or cartilage.
Sorry, no etymologies found.
On the lateral aspects of the parachordal cartilages the auditory vesicles are situated, and the mesoderm enclosing them is soon converted into cartilage, forming the cartilaginous ear-capsules.
The parachordal cartilages (Fig. 69) unite to form a basilar plate, from which the cartilaginous part of the occipital bone and the basi-sphenoid are developed.
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).
In front of the otic capsule is the paired pro-otic bone (p.o.); behind it at the sides of the parachordal ring is the paired ex-occipital (e.o.); in front of the cranium box, and behind the nasal capsules, is a ring of bone, the (median, but originally paired) sphenethmoid (s.e.).