Rapankistrodon

Rapankistrodon is a genus of extinct, venomous snake from the Late Cretaceous period, approximately 70 million years ago. It is known from a single fossil specimen found in the Hell Creek Formation of North Dakota, USA. The genus name, Rapankistrodon, is derived from the Greek words "rapankos," meaning "to strike," and "istros," meaning "snake," reflecting the snake's venomous nature.

Rapankistrodon is notable for its unique morphology, particularly its elongated, slender body and relatively small head. The snake is estimated to have been around 1.5 meters in length, making it one of the smaller known venomous snakes from the Late Cretaceous. Its venomous nature is inferred from the presence of venom glands and fangs, similar to those found in modern venomous snakes.

The fossil specimen of Rapankistrodon consists of a nearly complete skeleton, including the skull, vertebrae, ribs, and limb bones. The snake's teeth are also preserved, showing a unique pattern of serrations and grooves that likely aided in venom delivery. The fossil provides valuable insights into the diversity of venomous snakes during the Late Cretaceous and contributes to our understanding of the evolution of venomous snakes.

Rapankistrodon is one of several venomous snake genera known from the Late Cretaceous, including Dineobellator, Dracopristis, and Selenophidium. These snakes represent a diverse group of venomous snakes that evolved during a time of significant ecological and environmental change, including the Cretaceous-Paleogene extinction event. The study of these extinct venomous snakes helps scientists better understand the evolution of venomous snakes and their role in ancient ecosystems.