Australia's Marine Giant
Family Dolichorhynchopidae, Welles
The pliosaurs were related to the plesiosaurs but highly distinct in their
morphology. As plesiosaurs tended toward long necks and small heads, a
diet of fish and a physiology adapted to short bursts of high speed, so
the pliosaurs were the exact inverse.
They developed massive heads on short, stout necks, often specialised in
cephalopod prey, and were adapted to long periods of fast cruising. The
taxonomic structuring of the Mesozoic marine reptiles is long overdue for
thorough comparative review, and this work is under way in some
localities. Presently, Kronosaurus is placed with Dr Sam Welles' 1962
diagnosis of the Family Dolichorhynchopidae.
Kronosaurus queenslandicus was named in 1901 from a fragment of jaw with
six embedded teeth found near Hughenden, Queensland, Australia, by A
Crombie in 1899. It was described by Dr Longman, then Director of the
Australian Museum, who assessed it as an ichthyosaur, but following the
discovery of other fragments he corrected his diagnosis in 1924.
The most famous specimen was found in the limestone country north of
Richmond and was excavated in 1931-32 by an expedition from Harvard
University's Museum of Comparative Zoology. It was shipped to the United
States for three years of preparative work, and despite the name of the
institution no comparison was ever made between the giant display-quality
specimen and the type materials. For this reason the ascription must be
viewed as tentative, and a new generic name may one day have to be found.
Kronosaurus as mounted at the HMCZ measures 42'/12.8m and is probably the
most massive marine reptile that ever lived. The head alone measures
9'/2.7m, fully a quarter of the body. The skeleton was almost complete,
missing parts of the forepaddles and probably the end of the tail. These
were reconstructed and the display is a little misleading in that
knowledge of the animal seems more complete than it really is.
The specimen was removed from Australia without licence, and without
Australian scientists or institutions being involved, a situation the
local scientific community has never been happy about. If further
specimens come to light they will definitely remain in the country.
The animal has been assessed by the rounded teeth at the back of the jaws
to belong to the 'crush-guild,' a predator on the plentiful shoals of
ammonites that swarmed in the shallow epicontinental sea that had
transgressed much of north-eastern Australia in the Early Cretaceous,
sharing this biozone with elasmosaurs and ichthyosaurs.