Australia: The Land Where Time Began

A biography of the Australian continent 

Lungfish - Dentine-Covered Palates

Of the 3 known Early Devonian lungfish, all are found in southeastern Australia. All are primitive dipnoans with powerful crushing dentitions of thick dentine sheets covering the palate and the bighting surface of the lower jaw. In 2 of these genera the skulls are known and show the primitive condition of the bone pattern, with many small bones around the snout and the front of the skull roof. Dipnorhynchus ("2 lungs snout") is the best known. 3 species of this genera are known from the Taemas-Wee Jasper and Cooma regions of New South Wales and the Buchan district in eastern Victoria. All have a strong palate with bulbous tuberosities for crushing food, working like a nut-cracker, crushing hard-shelled animals.

Speonesydrion had a skull roof pattern similar to Dipnorhynchus, but the palate and lower jaw have rudimentary rows of tuberosities, forming the primitive plan for a crushing tooth-plate.

Ichnomylax is known only from a single specimen of 1 side of a lower jaw, from near Bell's Point, Warratah Bay, Victoria. It has a bulbous crushing heel covered with dentine on the inside of the lower jaw, and tooth ridges.

Sources & Further reading

John A Long The Rise of Fishes - 500 Million years of Evolution, University of New South Wales Press, 1995

Dipnoi