Umoonasaurus
Umoonasaurus, graphic reconstruction
Umoonasaurus is a genus of Pliosaur ( Pliosauridae ), extinct diapsiden reptiles from the Lower Cretaceous of southern Australia. The only known way is Umoonasaurus demoscyllus from which a nearly complete and Opalised to about 85 percent and a plurality of skeletal part skeletons were found. The Opalskelett also represents the most complete skeleton of a vertebrate animal opal, which is known worldwide.
Features
Umoonasaurus was a relatively small Pliosaur with a body length of about 2.5 meters. The outstanding feature compared to other plesiosaurs is the existence of a bone ridge along the midline of the skull and a bone comb pair over the eyes.
Unlike other Rhomaleosauridae some typical features of living in the Jura representative of the group were not trained in this genus. These include the large head and short neck as well as the tendency to gigantism, so the development of giant forms, as was the case with the approximately seven meters long Rhomaleosaurus.
Paleoecology
Umoonasaurus lived together with other Plesoisauriern and some ichthyosaurs in a cold body of water that was characterized by seasonal temperatures near freezing. This is in stark contrast to the climate conditions that tolerate extant aquatic reptiles. The forms must have been adjusted accordingly to these conditions, such as specialized physiological mechanisms such as endothermic or behavioral strategies such as seasonal migrations. Umoonasaurus was also apparently endemic to the area of the Bulldog Shale ( Bulldog Shale ) in what is now South Australia.
Taxonomy and systematics
Umoonasaurus
Rhomaleosaurus megalocephalus
Rhomaleosaurus victor
Macro Plata
Rhomaleosaurus zetlandicus
Leptocleidus
The opal outer skeleton was in 1987 by a miner in Coober Pedy in the Eromanga Basin ( the former Eromanga Lake ) and have been sold to the Opalhändler Andrew Cody in Melbourne, the first kept it in his private collection. In 1993, the skeleton of the Australian Museum in Sydney was purchased. There it is issued by the nickname, Eric '. The first description of the species was only in 2006 by Australian paleontologist Benjamin P. Kear and colleagues in Biology Letters. The first description was carried out on the basis of the skeleton described (Australian Museum F99374 ) as the holotype, another, also opalised -grown individual in the South Australian Museum ( P23841 ), a third skeleton of the region Curdimurka ( P31050 ) and a cub from the region Neale River. All Locations lie in the Bulldog Shale in northern South Australia, which are assigned to the Lower Aptian to Lower Albian.
Umoonasaurus is attributed despite his relatively young age of about 115 million years ago, the early and original Pliosauriern ( Pliosauroidea ). It is assumed that it is both to the most primitive as well as the surviving representative of the longest Rhomaleosauridae.
The genus name Umoonasaurus is made up of the words Umoona that the area referred to in the Aboriginal language Antakirinja around the place where Coober Pedy, as well as the Greek sauros ( σαῦρος ) for " lizard". The species name is from the Greek demos demoscyllus ( δῆμος ) for "people" or " community " and Scylla ( Σκύλλα ), the name of a sea monster of Greek mythology.