Iguanodon bernissartensis

Overview

Iguanodon bernissartensis is a large herbivorous dinosaur with a spike-like thumb. Numerous skeletons from a coal mine at Bernissart, Belgium, revealed its body in detail. Fossil discoveries and museum displays made it famous together.^[1][2]

Key facts

Even within one hand, fingers had different roles. The thumb developed into a spike, the middle three fingers formed a supporting structure, and the fifth is described as flexible. A pointed structure and weight-bearing parts can be compared in the same hand.^[1]

Time and place

It is known from the Early Cretaceous of present-day Bernissart, Belgium. The institution places the fossil-bearing layers around the late Barremian to early Aptian. They introduce the European dinosaur world around 120 million years ago.^[2][3]

The time range describes source context, not the complete duration of this species.

Size, form and skeleton

A toothless horny beak sits at the front of the snout, and the thumb resembles a conical spike. The institution gives adult lengths of approximately 9–11 m. A broad trunk, legs, and five differently shaped fingers form the large body.^[1][2]

Habitat and reproduction

This large herbivorous dinosaur processed plant food. A horny beak occupied the front of the mouth, with chewing teeth farther back. The institution describes replacement teeth taking over as existing teeth wore down, connecting feeding with tooth replacement.^[2]

Fossil discovery

The Bernissart coal-mine skeletons became important evidence for researching and displaying large dinosaurs. Unlike earlier upright mounts, modern reconstructions show a nearly horizontal spine. Changing how bones were connected changed the picture of posture in life.^[1][2]

References

1. Institute of Natural Sciences, Belgium — Iguanodon from Bernissart
2. Iguanodon bernissartensis collection record
3. International Commission on Stratigraphy (2024) — Geological time chart
4. McClung Museum — Eddie the Edmontosaurus

Research questions

Why can the same skeleton be mounted in different postures? Researchers compare spinal connections with how legs and fingers supported the body. The history of old displays reveals changing interpretations of dinosaur bodies.^[1]

Observation

Move your gaze from the pointed thumb to the middle three fingers and outer fifth finger. Follow the back line from the head through the long trunk to the tail to reveal the body’s supporting arrangement.^[1]