The Chaetognath Sagitta
![Black and white image of a long rod-like object with fine, curved spines protruding from the sides.](/sites/default/files/styles/embed_portrait_lg_1x/public/photos/MEB_back.png?itok=W1IpHiX_)
Chaetognaths, or arrow worms, have a distinct jaw structure composed of dense protein matrix and a fibrous substance called chitin. These organisms display an ambiguous set of developmental and morphological features, making them difficult to categorize on the Tree of Life.
Chaetognaths, or arrow worms, have a distinct jaw structure composed of dense protein matrix and a fibrous substance called chitin. These organisms display an ambiguous set of developmental and morphological features, making them difficult to categorize on the Tree of Life.
Date:
21 December 2018
Credit:
Photo: Zatelmar (Wikimedia)
Tags
Research