The sarcopterygian lungfish appeared in the Early Devonian, and their diversity increased by the Late Devonian, but the extant groups are only three genera and six species ³⁾. Only two species, Scaumenacia curta and Fleurantia denticulata, are known from the Late Devonian Escuminac Formation of Miguasha ³⁾, Canada, which is known for many Devonian fossils ^{1), 2), 3)}.

Scaumenacia is probably the best known lungfish of the extinct dipnoi ³⁾.

The larger adult could reach 65 cm in length ³⁾. Scaumenacia has typical sarcopterygian fleshy and long paired fins, pectral and pelvic fins. Furthermore, it has independent unpaired fins, two dorsal fins, a caudal fin and an anal fin, whereas the lungfishes after the Devonian have a long fused median fin, that is, a fusion of dorsal and caudal fins, or anal and caudal fins ^{1), 2)}.

The caudal fin is a reduced heterocercal ¹⁾. It appears too small for the overall balance of the body.

All exant lungfish are freshwater inhabitants, and Scaumenacia also seems to be fresh water, but the Escuminac Formation is a marginal marine environment ²⁾, suggesting that Scaumenacia lived in brakish water or moved between fresh and marine water.

Although Scaumenacia was large in size, it was not a predator that prey on other fish, but seemed to feed on "clam shrimp" (nickname of Asmusia), a small crustacean with bi-valves ^{2), 3)}.

Lungfish are often thought to dig burrows and hibernate there during the dry season, however there is no evidence that Scaumenacia dug burrows ^{2), 3)}. Scaumenacia could gulp air, but did not dug burrows ^{2), 3)}. Scaumenacia was a benthic fish preying on small invertebrates in the mud.