Piotr Ivanov

Piotr Pavlovich Ivanov (; 9 April 1878 – 15 February 1942) was a Soviet embryologist and a professor. He studied segmentation in annelids and arthropods and proposed the differentiation of two kinds of segments in segmented organisms and the developmental (or ontogenetic) idea of heteronomous metamery where several segments fuse to perform a common function. Provided by Wikipedia