Judging from the small limbs and overall size, it appears to be a large aquatic salamander, similar to Necturus maculosus, the mudpuppy. These have a pretty cosmopolitan distribution in North America, including into southern Canada. I can't tell from the photo if it has external gills.
Hard to tell without a clearer picture, but the size and color pattern seem to match the description for the Plain-bellied Watersnake.
See for example the following picture from the Virginia Herpetological Society:
I assume from the location being in something called a swamp that the habitat (in and near slow moving bodies of water) also fits.
Secondary ectothermy has been suggested in living crocodylians by Seymour et al. (2004). Their rationale is based on:
Presence of a 4 chambered heart (otherwise only found in endotherms)
Post-cardiac shunting via the foramen of Panizza and "cog-tooth" valve, which develop secondarily in crocodylians
Lung structure and ventilation during locomotion
It's a self-defense mechanism, the tail falls off during threatening situations, to which the reptile responds by excessively contracting the tail muscles. This process is known as "Autotomy", or "Self-Amputation". Other animals have got "stronger tails" simply because such self-defense mechanism hasn't been developed.
There is no evolutionary "ratchet" that prevents a life form from evolving "backwards". However, it is statistically unlikely because it would pretty much require all of the environmental factors that changed during the transition from "cold blooded" to "warm-blooded" to change back in the reverse order, because all of those factors contributed to the ...
I finally got frustrated enough to dig up A Revision of the Liasis childreni species-group (Serpentes: Boidae) L.A. Smith, 1985 - the original paper that split up this species complex, and when even Smith made primary determinations off of pattern and color alone, I took matters into my own hands and dug into the his raw data.
I have compiled the mean ...