Acrocanthosaurus

Acrocanthosaurus was one of the largest apex predators of Early Cretaceous North America. Stretching over eleven metres in length and weighing several tonnes, it was characterized by elongated neural spines projecting from its neck, back, and tail vertebrae. Rather than forming a thin cooling sail, these spines were anchored by thick ligaments and muscles, creating an imposing muscular hump or ridge along its spine. Acrocanthosaurus possessed an elongated skull lined with curved, serrated teeth designed to tear deep gouges in prey. Excellent fossil specimens, including exceptionally preserved skulls and trackways attributed to it in Texas, demonstrate that it hunted huge sauropods such as Sauroposeidon as well as ornithopods like Tenontosaurus across coastal plains and river floodplains.

Its tall neural spines along the vertebrae supported a powerful ridge of muscle down its back.

Where and when

Acrocanthosaurus lived in the Early Cretaceous, from 115 to 110 million years ago (Aptian-Albian age). Its remains come from United States, in the Antlers Formation.

The numbers

Length 11 m (estimates run from 11 to 12 m). Mass about 5 t. Hip height about 3.4 m. That is 6.6 human-lengths, or 1.01 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

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