Istiorachis macarthurae Istiorachis

"sail spine"

You 1.8 m (5.9 ft) tall
Istiorachis 5 m (16.4 ft) long
3 people holding hands
Length
5 m (16.4 ft)
Period
Early Cretaceous (145–100 Mya)
Place
United Kingdom
Food
Herbivore
Clade
Dinosauria

Istiorachis (meaning “sail spine”) is an extinct genus of iguanodontian ornithopod dinosaur from the Early Cretaceous (Barremian age) Wessex Formation of the Isle of Wight, England. The genus contains a single species, Istiorachis macarthurae, known from a partial postcranial skeleton including several vertebrae, incomplete ribs, and part of the pelvis. Its vertebral are notably elongated, giving the animal a ‘sail-backed’ appearance.

What we know

  • Named by Lockwood, Martill & Maidment, 2025.
  • Fossils found in United Kingdom.