 Olson made many inferences on the paleoecology of the Texas Red beds and the role of Dimetrodon within its ecosystem . He proposed several main types of ecosystems in which the earliest tetrapods lived . Dimetrodon belonged to the most primitive ecosystem , which developed from aquatic food webs . In it , aquatic plants were the primary producers and were largely fed upon by fish and aquatic invertebrates . Most land vertebrates fed on these aquatic primary consumers . Dimetrodon was probably the top predator of the Red Beds ecosystem , feeding on a variety of organisms such as the large shark Xenacanthus , the aquatic amphibians Trimerorhachis and Diplocaulus , and the terrestrial tetrapods Seymouria and Trematops . Insects are known from the Early Permian Red Beds and were probably involved to some degree in the same food web as Dimetrodon , feeding small reptiles like Captorhinus . The Red Beds assemblage also included some of the first large land @-@ living herbivores like Edaphosaurus and Diadectes . Feeding primarily on terrestrial plants , these herbivores did not derive their energy from aquatic food webs . According to Olson , the best modern analogue for the ecosystem Dimetrodon inhabited is the Everglades . The exact lifestyle of Dimetrodon ( amphibious to terrestrial ) has long been controversial , but bone microanatomy supports a terrestrial lifestyle , which implies that it would have fed mostly on land , on the banks , or in very shallow water . 
