| phylogeography of the flat-tailed horned lizard (phrynosoma mcallii) and systematics of the p. mcallii-platyrhinos mtdna complex. | two species of horned lizards are sympatric along the periphery of the salton trough. phrynosoma mcallii, endemic to the trough, is of conservation concern because its limited habitat has been fragmented by human activities. a more common and widespread species, phrynosoma platyrhinos, occurs around the periphery of the trough and much further to the north. the two species are syntopic at a few localities, where morphological intermediates have also been found. here, we used nested clade phyloge ... | 2006 | 16689900 |