primitive costal arch
Any of the arches formed from the costal processes or elements that give rise to the ribs in the thoracic region of the embryonic vertebral column.
Learn The History Of The New York Times Crossword PuzzleThere are plenty of crossword puzzles in publications across the country, but when we think of the pinnacle of puzzledom (Not officially a word, but, perhaps, it should be?), the purveyors of the most preeminent puzzles, we bow to The New York Times (NYT). But how did it all begin?
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.