Warkalania

Although the presence of meiolaniids in the Riversleigh fauna had been known on the basis of fragmentary remains since at least 1987, the first diagnostic remains were discovered by Neville Pledge in the form of a partial skull from strata dating to the late Oligocene to early Miocene. These remains were described by Eugene S. Gaffney, Michael Archer and Arthur White as a new genus of meiolaniid turtle they named Warkalania carinaminor. The holotype is specimen QMF 22649, a right squamosal bone including the tympanic cavity and various scales of that area, and was discovered at the Pancake Site in Queensland. Additional material has also been reported, such as QMF 22650, a left squamosal that may have belonged to the same individual as the type specimen. The other referred specimens include various skull bones including the parietals, a quadrate bone and the squamosal of at least one other turtle. The genus name Warkalania combines the word "Warka" meaning "turtle", which Gaffney and colleagues attribute to a no closer specified Australian Aboriginal language of the Queensland region, and "lania". The suffix -lania is a common component in the names of meiolaniid turtles, also used in Meiolania, Gaffneylania and Niolamia. The meaning of the term is however interpreted differently by various authors, partly due to the lack of an etymology given in the description of Miolania. In the description of Warkalania, the word is translated as "butcher" from the Latin "lanius", but other researchers point to Owen's description of Megalania to argue that the suffix is actually derived from the Greek word for "to roam about". The species name of W. carinaminor on the other hand simply translates to "small ridge", a reference to the fact that this genus didn't possess the large horns of other meiolaniids. ==Description==

The skull of Warkalania is highly ankylosed, entirely obscuring the sutures between the individual skull bones. Consequently, Gaffney and colleagues describe the skull largely on the basis of the contacts between the overlying scutes, which are alphabetically labeled. The individual scale areas are separated by the presence of shallow grooves, similar to Ninjemys and Niolamia and different from the raised ridges of some individuals of Meiolania platyceps. One of the referred specimens preserves scale X, which is located in the central portion of the skull between the scales D and G, likely covering the back of the frontal bones and the front of the parietal bones. Scale X is of similar size to the same scale in Meiolania platyceps from Lord Howe Island and bears the same kind of conical protrusion on its surface, though smaller than in the later species. While only a single scale X is present, the scales D and G are paired and appear to meet their respective opposite along the midline of the skull. Overall this gives the skull of Warkalania a less ornate appearance compared to the elaborate crests in Neiolamia and Ninjemys or the distinctive bull-like horns of Meiolania. ==Phylogeny==

Gaffney and colleagues found that Warkalania shared several features of its horns with Meiolania, including the size of the A horns, the fact that the B horns don't project laterally and the relatively flattened D scales. Considering these characters to be synapomorphies, they concluded that Warkalania was the closest relative to Meiolaniato the exclusion of both Ninjemys and Niolamia. This was later corroborated by additional studies including the phylogenetic tree recovered by Sterli et al. in their description of Gaffneylania. Both results are shown below, with the more recent tree showing the varying positions that Gaffneylania was found in due to its incomplete nature. ==Paleobiology==

Besides the material that forms Warkalania, various other meiolaniid remains are also known from Riversleigh that cannot be confidently assigned to the genus due to the lack of overlapping material. ==References==