It was one of the largest amphibians ever growing up to over 4 metres in length. It would have been a very slow walker given its legs puny size and their unstrategic postioning. This may mean that it lived in slow moving or still waters which are calm environments so it did not have to use its legs very often meaning that it definitely spent the vast majority of its life underwater. Like most amphibians today it can breathe on land AND underwater but it would be sluggish over land meaning that the only time it would go on land would be if its lake or river dried up or there was no more food ar mates around. This amphibian would have flourished in the warm, wet environments that covered the entire planet when it lived in the Carboniferous. There would have surely been no short supply of fish to go around and since it was one of the largest amphibians in the carboniferous. It would have had very few natural predators so the only threat to it would be other Eogyrinus or large arthropods and amphibians.