User:Ankylosaur Enthusiast/sandbox4

History and naming
The holotype of Pengana (QMF16865) was collected from the 'Sticky Beak site' at the Riversleigh World Heritage Area, Queensland. It consists of the distal end of the left tibiotarsus. A possible second specimen (ARl 6794) is known, a distal femoral fragment from the 'White Hunter site'. Both the Sticky Beak and White Hunter sites are late Oligocene in age, making Pengana the oldest known accipitrid from Australia.

In 1993, ornithologist and palaeontologist Walter E. Boles described Pengana roberbolesi as a new genus and species of accipitrid based on these fossil remains. The genus name is stated to have been derived from an Aboriginal word for hawk, although no language in particular was specified. The species name honours Richard Boles, the late father of Walter E. Boles.

Description
Pengana was a large acciptirird, said to be larger than any living Australian acciptirid except for the wedge tailed eagle and white breasted sea eagle. The distal end of the tibiotarsus has a distal width of 6.4 mm (0.25 in), with an external condyle depth of 11.8 mm (0.5 in) and an internal condyle depth of 13.2 mm (0.52 in). It has an overall flat and rectangular appearance. The supratendinal bridge is almost horizontal, angled at 30°. The distal opening of the supratendinal bridge is more medially placed and has a proportionally greater width compared to Geranospiza and Polyboroides. The shaft of the tibiotarsus is compressed anterioposteriorly (front to back). The distal condyles are flattened in a mediolateral direction and are parallel to the proximodistal (from the centre to the distal end) midline of the shaft.

Paleobiology
Similar to harrier and crane hawks, the distal tibiotarsus has a horizontally oriented supratendinal bridge and parallel condyles. These features would have allowed for the leg to be swivelled backwards and sideways to a greater than in other acciptirids. well adapted to reaching into holes and crevices and extracting prey. Long legs permitted it to raid nest hollows at least 400 mm deep