level

It is known that climate change has an effect on many Deltas all over the world. Egyptian Nile Delta, one of the most dangerous places which may be suffered from risks of climate change. In the current work, an attempt to study the effect of climate change on the Nile Delta has been discussed.

Knowledge on the regularities of vegetative propagation and comprehension of the osculum (oscula) and subosculum structural-functional positions and interrelations in the skeleton structure have made it possible to specify the organization levels in the Late Cretaceous hexactinellids: the unitary (solitary, perifrontal and autonomous forms), transitory (solitary, autonomous and colonial forms) and colonial (primary and true colonies) ones.