Early amphibians were “surprisingly sprightly” according to a report in New Scientist, 25 October 2003, p15. The first amphibians to make the move from water to land are usually depicted awkward sluggish creatures that had trouble keeping their body temperature high enough to remain active. Robert Carroll of McGill University, Canada has studied the skeletons of fossil amphibians and found the joints between their limbs and backbones were sufficiently robust to carry them around on land very well. He also experimented with models of fossil amphibians, which were up to one metre (3ft 3in) long, to see how much heat they could absorb. His results indicate they could have raised their body temperature by up to 13 degrees Celsius by basking in the sun which would enable such large animals to move about in cooler water for an hour, just as crocodiles do today.
Editorial Comment: Living amphibians are well designed for the semi-aquatic ecological niche they live in. This research indicates fossil amphibians were similarly well designed for their environment.
In fact, there is no such thing as a “primitive” partially evolved animal. All known living animals are fully formed, functional creatures, and the same applies to fossil creatures when they are preserved well enough to study. This is and always has been the bug-bear of evolution. (Ref. amphibian, fossil)