Horned Lizard vs Thorny Devil

No. They are both lizards, but they sit in different families on different continents and are only distantly related within the reptiles. The horned lizard is an American phrynosomatid, close to the fence and spiny lizards. The thorny devil is an Australian agamid, close to the bearded dragons and water dragons. Their near-identical appearance, flat wide body, spines, horns, ant diet, and skin that wicks water to the mouth, evolved separately in each lineage because both animals face the same challenge of living as a slow, exposed, ant-eating lizard in hot dry country. It is one of the clearest reptile examples of convergent evolution.

No, blood-squirting is unique to the American horned lizards. When grabbed by a fox, coyote, or dog, about eight of the roughly twenty horned lizard species can restrict blood flow from the head until vessels around the eyes burst, firing a thin stream of blood up to about a metre and a half, aimed at the attacker's mouth and carrying compounds from the lizard's ant diet that taste revolting to canids. The thorny devil defends itself only with camouflage, its dense spines, wedging into a crevice, and its decoy false head, the spiny lump on the back of its neck that it offers to a predator while protecting its real head between its front legs.

Both use the same remarkable trick, evolved separately: skin that moves water to the mouth by capillary action. The surface of the lizard is covered in a network of tiny grooves and channels between overlapping scales, and when dew condenses on the animal overnight, or it stands on damp sand, or a little rain falls, the water is drawn into these channels and wicked along the body to the corners of the mouth, where the lizard laps it up. This lets a horned lizard or a thorny devil rehydrate without ever finding a pool, which matters in habitats where standing water may be absent for months.