Australia: The Land Where Time Began

A biography of the Australian continent 

Late Cretaceous Marine Lizards - Mosasaurs and Dolichosaurs

The fossil record of lizards from the Late Cretaceous of Australia contains only mosasaurs (Mosasauridae) and dolichosaurs, both predators being related closely to snakes and monitors. Worldwide they were the dominant group of Mesozoic marine reptiles in faunas from the Late Cretaceous.

The Winton Formation has produced the only known vertebra, a bit over 5 mm, of a dolichosaur in Australia. Though dolichosaurs were typically marine, this find is evidence that they did enter freshwater environments, at least occasionally.

A fragmentary forelimb, an ulna and phalanx, is the first evidence found in the Molecap Greensand of Western Australia of the presence of dolichosaurs. Possible affinity to Platecarpus is suggested by the slender proportions of their bones. The small-bodied plioplatecarpine mosasaur, about 3 m long, was widely distributed from the North American arctic south to Antarctica. A series of 10 articulated trunk/tail vertebrae of a mosasaur have been found in the Molecap Greensand at a site to the north of Dandaragan. According to the authors³ this material appears to be from a plioplatecarpine of moderate size.

Mosasaur remains of Masstrichtian age have been found in the Korojon Calcarenite, a unit that stratigraphically underlies the Miria Formation. Among these remains an isolated dorsal vertebra of a mosasaur was found. Sporadic material that included 3 associated trunk/tail vertebrae in a deposit on Cardabia Station in the Giralia Ranges. These vertebrae, that were especially well preserved, appear to be from a large mosasaurid about 6-8 m long, of uncertain affinity. The Miria Formation has also produced many other fragmentary mosasaur vertebrae. Though taxonomically indeterminate they suggest the presence of  a small-bodied probable plioplatecarpine

 

Triassic Australia

Jurassic Australia

Cretaceous Australia