Ophidian

Vertebral structure is critical for the identification of fossil snakes, because vertebrae are among the most easily fossilized parts of ophidians.

It has long been known that ophidians have lost not only their front legs but also every embryonic trace of these limbs and their associated shoulder girdle (to such a degree that we cannot determine how many cervical vertebrae they have).

Siamese or double monsters are well known in saurians, chelonians, and ophidians, as are bicephalic, two-tailed and conjoined bodies (thoracodymus, ischiodymus, etc.).

The ophidian beast began to glow eerily, and Aaron could discern a fine webwork of veins and capillaries running throughout the creature's body.

A less obvious asset of snakes is their very light and supple jaws, which arose in the course of ophidian evolution to permit the ingestion of extraordinarily large meals (at maximum, more than 100% of their body mass).

Another ophidian deity recognizable in Classic reliefs is the Feathered Serpent, known to the Maya as Kukulcán (and to the Toltecs and Aztecs as Quetzalcóatl).