The living Australian lungfish, Neoceratodus, is regarded as
the most primitive existing member of the group - that is,
it is least changed from the originallungfish body plan. It
reaches 1.8mJ6ft in length and weighs more than 40kg/88Ib.
Ceratodus is one of its ancient cousins, but it attained
only about one-third the size. Like other lungfish, -itcould
breathe air and had 1£rge, plate-like teeth for grinding
shelled invertebrates. Early evidence of Ceratodus comes
from the Triassic Period, some 240 million years.ago.
The genus went extinct in the.Early Tertiary Period aftera
very long-lived existence of more than 180 million years.