Why do mammals have more invertebrates than vertebrates?

The rest were originally lumped as"invertebrates", but the Echinoderm s and others are reckoned more closely related to vertebrates than to insects or molluscs. Classifications vary, but mostly four phyla including chordates are lumped together as Deuterostome s. read more

A vertebrate respiratory system relies on organs like lungs or gills for gas exchange in the blood stream, whereas invertebrates have simple respiratory systems. Insects generally tracheal systems that branch from openings in the surface called spiracles directly to their internal organs. read more

Vertebrates have a versatile support system. As a result, vertebrates have the capability to develop faster and bigger bodies than invertebrates. Adaptation to the Environment . In contrast to invertebrates, vertebrates have a highly developed nervous system. read more