prechordaladj.
/priːˈkɔːdl/, U.S. /priˈkɔrd(ə)l/ 1. Embryology and Anatomy. Situated or occurring in front of the anterior end of the notochord. Cf. prochordal adj.
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1878 Philos. Trans. 1877 (Royal Soc.) 167 550 The prechordal part of the trabeculæ now exists as a high wall from the auditory to the nasal sacs.
1922 Amer. Jrnl. Anat. 31 55 The name prechordal plate will be used throughout this paper to designate the diffuse mass of tissue in which the notochord ends anteriorly.
1942 J. Needham Biochem. & Morphogenesis ii. 323 As the expansion proceeds, the mesoderm is tucked in underneath the neural axis, first the prechordal plate, then the notochord and somites, like the unrolling of a carpet.
1979 Jrnl. Embryol. & Exper. Morphol. 53 237 Induction of forebrain and optic vesicles is purely prechordal.
2003 Developmental Biol. 261 325/1 Vertebrate skeletal muscle is derived from multipotential cells in the prechordal and somitic mesoderm.
2. Biology. Occurring prior to the evolution of the notochord or of the chordates; lacking a notochord. Cf. prechordate adj. rare.
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1888 E. R. Lankester in Encycl. Brit. XXIV. 187/2 No other Vertebrata present larval forms which indicate the nature of the early ancestral history in what we may call præ-chordal times.
2002 Gen. & Compar. Endocrinol. 126 130 Phylogenetic consideration of the pituitary-like structures of prechordal animals is also presented.
This entry has been updated (OED Third Edition, March 2007; most recently modified version published online March 2022).
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adj.1878