Pseudalsophis thomasi

The genus name Pseudalsophis comes from the name of a genus of Caribbean snakes Alsophis due to their superficial similarities, combined with the Greek word pseudo meaning false. The specific name is in honor of the herpetologist Robert A. Thomas.[2][3][4]

Diurnal snakes, active throughout the day with the exception of hot midday hours. They can be found in rocky areas, deciduous forest, and dry grassland habitats. Foraging predators they feed on small animals such as lava lizards, geckos, and possibly invertebrates. Snakes are mildly venomous enough to endanger small prey items but not enough to harm a human. Thomas's Racers have no natural predators however they are preyed upon by introduced black rats.[3]

Thomas's racer is endemic to the islands of Santiago, Bartolomé, and Rábida. Its total estimated range is approximately 459 km² It is the more common of the two snake species found on Santiago and Rábida, the other being the much rarer Pseudalsophis hephaestus or Santiago racer. It is also the only snake species known to be present on Bartolomé.[3][4]