How did early trepostome bryozoans build large solid colonies?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Eurystomella bilabiata, a moss animal from the Order Cheilostomata. — moss animal *Eurystomella bilabiata*, a moss animal from the Order Cheilostomata.

Early trepostome bryozoans built large, solid colonies through the growth of long, slender zooids that grew together. As these individual zooids increased in length, they deposited diaphragms, which are transverse partitions, within their calcareous tubes. These structures, along with the calcified nature of the zooid walls, allowed the organisms to form the robust, solid colonial structures characteristic of the order Trepostomata.123