01/12/2020
Pilbara mulga monitor (Varanus bushi)
Varanus bushi is most similar to the stripe-tailed goanna (Varanus caudolineatus) and the pygmy Mulga goanna (Varanus gilleni) of all monitor lizards. However, the bush monitor can be distinguished from these other two species by some morphological and genetic differences.
Distinguished from most others by the combination of a longitudinally striped and only moderately spinose tail, unkeeled head and body scales, non-overlapping ventral primary scales, and an absence of longitudinal streaks on throat. Distinguished from V. gilleni by its slightly lesser average size, more elongate dorsal scales, more densely spotted venter and more irregularly spotted dorsum, less prominent linear patterning on the head and neck, and its more numerous presacral vertebrae, pedal subdigital lamellae and ventral scales. Males are further distinguished from V. gilleni by having hemipenes with an undivided inner hemibaculum. Distinguished from V. caudolineatus by its slightly greater average and maximum size, proportionally shorter fore- and hind-limbs, more elongate snout, higher average midbody and ventral scale counts, higher average sub-digital lamellar counts on pes, more finely scaled and less rugose proximal portion of the tail, more numerous presacral vertebrae, less conspicuously spotted head, more orderly alignment of dorsal pattern into transverse rows, and presence of transverse bands on the basal one-third of the tail. Males are further distinguished from V. caudolineatus by having a shorter hemipen*s with more numerous papillose distal frills.
©️ Pic credit : Chris Applin