(Kronus lizard - after the king of the Greek Titans).
Named By: Longman - 1924.
Classification: Chordata, Reptilia, Sauropterygia, Plesiosauria, Pliosauroidea, Pliosauridae.
Species: K. queenslandicus (type), K. boyacensis.
Size: Estimated between 9 and 10 meters long. Skull 2.7 meters long.
Known locations: Australia. Colombia.
Time period: Aptian to Albian of the Cretaceous.
Fossil representation: Two sets of remains and associated individual teeth.
is one of the more famous fossil discoveries to come from Australia,
and as a huge short-necked pliosaur, Kronosaurus
would have been an
apex predator of the waters it swam in. The teeth of Kronosaurus
conical and up to thirty centimetres long, although most of that was
root with up to twelve centimetres making up the exposed crown.
Interestingly the teeth of Kronosaurus are quite
different to other
in that they are not serrated and do not have three facets.
The teeth may suggest that despite its large size Kronosaurus
seized smaller to medium sized prey which could then be manipulated to
be swallowed. The only way that Kronosaurus could
have fed from
larger prey would be to clamp on with its jaws and then use brute
strength from its body to tear off a chunk of flesh by twisting or
rolling. Either way it seems that Kronosaurus may
have eaten in a
similar manner to a crocodile.
One prey type for Kronosaurus seems to have been the long necked elasmosaurid plesiosaurs that were quite common in the southern oceans of the Cretaceous. Evidence for this predation comes from the skull of an Eromangasaurus that seems to have Kronosaurus bite marks. Also the fact that Eromangasaurus is only known from a skull might suggest that the head was torn off in the Kronosaurus attack.
Initial size estimates for Kronosaurus placed it at just under thirteen meters long. However further study combined with a better understanding of pliosaur remains in general resulted in a reduction in this estimate to somewhere in the region of nine to ten meters long. This estimate is universally accepted as being more accurate, and although the upper size is reduced to ten meters, Kronosaurus was still big for a pliosaur and was much bigger than Liopleurodon which is often incorrectly credited as the biggest pliosaur ever. An even bigger pliosaur than Kronosaurus however is the one that has been dubbed 'Predator X', which is now classified as a species of Pliosaurus.
- Some Queensland fossil vertebrates. - Memoirs of the Queensland Museum 7(1):16-25. - H. A. Longman - 1924.
- Ein großwüchsiger Pliosauride (Reptilia: Plesiosauria) aus der Unterkreide (oberes Aptium) von Kolumbien. - Courier Forschungsinstitut Senckenberg 145:1-25. - O. Hampe - 1992.
- Cretaceous marine reptiles of Australia: a review of taxonomy and distribution. - Cretaceous Research 24: 277–303. - B. P. Kear - 2003.