heterochronia

[hĕt′ə-rō-krōnē-ə]

n.

The origin or development of tissues or organs at an unusual time or out of the regular sequence.

Related formshet′er•o•chronic (-krŏnĭk) null adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.