Is this a case of taxon exclusion?
Perhaps… and yet, given the present taxon list, the thorny devil and the flying dragon are more closely related to each other than to any other taxa in the large reptile tree (LRT, 1087 taxa, Fig. 7).
With taxon exclusion, sometimes things like this happen.
The large reptile tree (LRT, 1087 taxa) has just a few agamid iguanids in its taxon list. The addition of the Australian thorny devil, Moloch horridus (Gray 1841), and its nesting with the SE Asian gliding dragon, Draco volans, reminds us that other well-known agamid lizards, like bearded dragons, would probably nest between them.
It’s also notable
that the thorny devil does not nest with the similar but more distantly related horned lizard (Phyrnosoma, Fig. 6) of Western North America.
Lyriocephalus is the last common ancestor
to Draco and Moloch in the LRT. We looked at the skull and skeleton of Lyriocephalus (Fig. 5) earlier here.
Curious if the ancestors of Moloch
experienced a loss of jungle habitat and so adapted to scrub and dessert niches, since sisters and ancestors are jungle iguanids.
For that matter
desert-dwelling horned lizards are most closely related to jungle-dwelling chameleons, like Trioceros, in the LRT (Fig. 7). Did horned lizards experience a similar loss of jungle? If so, that probably happened before the advent of the odd hands and feet of extant chameleons.
Gray JE 1841. Description of some new species and four new genera of reptiles from Western Australia, discovered by John Gould, Esq.: Ann. Mag. Nat. Hist. (1) 7: 86-91.