The following has been taken from Paul Speirs' website and is one of the most useful bits of information I have ever found. Because Paul changes servers from time to time, I have taken the liberty of reproducing it here. However, this is the latest address I have for the real thing which will be more up to date than mine, so please take a look at it; Paul is, after all, an Australian!
http://pspeirs.cable.nu/redirect.asp?dest=pogonakey
The following information has been taken from Harold Cogger's excellent book Reptiles and Amphibians of Australia. I make no claim whatsoever to any of the information contained here. The information supplied is purely for educational purposes only.
It has also been noted that the P.brevis or P.henrylawsoni is not mentioned in the following text. There has been a great deal of confusion and infighting as to the proper taxonomy of the animal and as such never made it into the Cogger book proper, although it is mentioned in the Appendix as follows:
Pogona
henrylawsoni Wells and Wellington, 1985
Description: Similar in most respects to Pogona minor. It is distinguishable from all other species of Pogona by the combination of 18 or fewer lamellae under the fourth toe and 12 or fewer preanal and femoral pores. Hindlimb about 60%, tail about 90% of snout-vent length. 15cm (snout-vent).
Distribution: Central Qld.
Habit: Black soil plains.
Paul has/ had a PDF file on his site that gives information on the P.henrylawsoni formerly named brevis. Unfortunately I can't make that information available.
Key 1
Dorso-ventral margin of body demarcated by an orderly row of enlarged conical spines (Fig a) . . . Key 2
Dorso-ventral margin of body with several rows of spines widening to a broad band anteriorly behind the axilla (Fig b) . . . Key 5
No enlarged gular spines in centre of throat (Fig c) . . . Key 3
Enlarged gular spines in centre of throat (Fig d) . . . Pogona vitticeps
Spine rows of head with smaller spines that are not usually contiguous (Fig e) . . . Key 4
Spine rows of head strongly defined with contiguous, stout, conical spines (Fig f) . . . Pogona mitchelli
An additional nuchal row of spines parallel to the vertabral column on each side (Fig g) . . . Pogona minimus
No nuchal row of spines parallel to the vertebral column, at most only a clump of spines at termination of transverse nuchal row (Fig e) . . . Pogona minor
Enlarged gular spines across centre of throat (Fig d) . . . Key 6
No enlarged gular spines in centre of throat (Fig c) . . . Pogona microlepidota
Conspicuous narrow white bands across back and tail . . . Pogona nullabor
No conspicuous white bands on back and tail . . . Pogona barbata
