Is Nova Scotia fossil ‘Superstar’ from an early human ancestor?

Yesterday, reports came out that a rare fossil had been discovered during an otherwise routine dog-walking excursion.

So far, "Superstar" (as it has been nicknamed) consists of a rib cage, a section of spine, a partial sail and a skull, and is the first fossil of a "sail-backed reptile" ever found in Nova Scotia. From the small size of it, paleontologists at the Museum of Natural His­tory in Halifax believe it was likely very young, given that some of these species can grow to nearly 5 metres long and weigh close to 300 pounds.

Partial rib cage, shoulder blade and sail of 'Superstar' the sail-back reptile.

Sail-backed reptiles, like Dimetrodon and Edaphosaurus, although they may look like dinosaurs, and have appeared alongside dinosaurs in such movie greats as Journey to the Center of the Earth, and One Million BC, are not dinosaurs, and are not even considered to be lizards. They are mammal-like reptiles called synapsids.

Synapsids are "transitional fossils", since there are synapsid species that clearly show intermediate steps of evolution between early land vertebrates (the creatures that first crawled out of the oceans) and mammals.

The Dimetrodon, which is known as a very early ancestor of human beings, is a good example of this.

The fossil found in Nova Scotia Thursday is likely a Dimetrodon.

The structure of Dimetrodon's nasal cavities suggest that they had mucous membranes, and the prominent sail along their backs suggests the development of temperature regulation, which are both evidence of evolution towards warm-bloodedness. Also, it was likely that this species first developed different sizes of teeth — its name means "two shapes of tooth." It was this evolutionary step that allowed them to chew their food, breaking it down into smaller pieces for easier (and more efficient) digestion. In contrast, species that swallow their prey whole need to spend more energy on digestion, and therefore don't get as much out of the process.

The fossil still needs to be analyzed to determine exactly what species it is, but if I were a betting man, I'd put my money on Dimetrodon, since "trackways" (fossilized footprints) of that species have already been found in the area.

Regardless of what species it turns out to be, though, the find is significant because it is the first vertebrate fossil found there, and it provides another puzzle piece in reconstructing the paleontology of the area.