"A Sort of Odd Marine Dimetrodon"

In the summer of 1849, four people fishing at the entrance of St. Margaret's Bay, Nova Scotia, had an encounter with a sixty-foot long sea serpent:

"It was proportioned like an eel, i.e. tapering towards the extremities, with no caudal fin perceptible, but one very high fin, or a row of spines, each of about an inch in diameter at the base, erected along its back, serving indeed for a dorsal fin, like the folding fin of the Thynnus vulgaris, or albicore. The spinal erection seemed to occupy about one third of its length, each end of it being about equi-distant from the Serpent's extremities, and at a distance, somewhat resembling, in size and appearance, the sail of a skiff. The animal's back was covered with scales, about six inches long and three inches wide, extending in rows across the body, i.e., the longer diameter of the scale being in the direction of the circumference of the body. The color of the back was black. The men had no opportunity of seeing the belly, but what the Americans would call 'a smart chance' of becoming acquainted with the inside of it; for the creature, perceiving the boat, raised its head about ten feet above water, turned towards it, and opened its jaws, showed the inside of its mouth red in color and well armed with teeth about three inches long, shaped like those of a cat-fish. The men now thinking it high time to terminate the interview, pulled vigorously for shore, followed for some distance by the snake, which at length gave up chase and disappeared."

By the description of this sea serpent, with the high fins on its back, it most definitely doesn't sound like a "snake" as it is referred to in the end of the report. But then, what is it?

Bernard Huevelmans

Dr. Bernard Huevelmans, author of In the Wake of the Sea-Serpents, notes that the description seems to fit that of some fish. But what fish? He mentions the oarfish (a common 'explanation' for sea serpent sightings), but it does not match the description except possibly for the spines. He also rules out eels as they do not have scales and don't have spines like the creature. Could it be a sailfish? No, he said, because it wouldn't be able to raise its head ten feet out of the water so the witnesses could see its mouth.

Oarfish

Sailfish jumping out of the water.
The witnesses, however, said they only saw the creature's
neck 10 feet out of the water

What was it then? Was it a "sea monster" in the truest sense? Or a hoax, as Huevelmans suspected:

"If the description is truthful and accurate, it seems more to apply to a reptile, which can move its head on its neck. But as such an animal - a sort of odd marine Dimetrodon - has never been described by anybody else, even in a work of paleontology, this report is unacceptable and seems very suspect."

Dimetrodon