The crocodile mimic: a dinosaur built for the water's edge

Nature · Published 19 October 2026 Swipe more like this →

In short: Imagine a predator with the heavy build of a dinosaur but the specialized skull of a crocodile. Suchomimus, a massive theropod from the Early Cretaceous, possessed unique adaptations—from a terminal rosette of teeth to a powerful thumb claw—that allowed it to dominate the fluvial floodplains of ancient Niger.

Discovered in the Ténéré Desert of Niger, Suchomimus tenerensis lived approximately 112 million years ago. Its name, meaning 'crocodile mimic,' highlights its striking resemblance to modern crocodilians. Unlike most giant theropods, it featured an elongated, low snout with a flared 'rosette' at the tip. This structure housed numerous finely serrated, conical teeth, with the largest positioned at the front to facilitate a piscivorous (fish-eating) diet in shallow waters. The fossils originated from the Elrhaz Formation. These remains were first uncovered in 1997. A large thumb claw was spotted by David Varricchio. The team officially named the species in November 1998.

The animal's anatomy reveals a sophisticated balance of power and specialization. Its neck was relatively short but heavily muscled, supporting a skull reinforced by a closed secondary palate to resist torsional forces during hunting. Along its back, extended neural spines formed a low dorsal sail, which may have supported a skin crest. The animal possessed about sixteen dorsal vertebrae. Its humerus was only matched by Megalosaurus and Torvosaurus in size. The pelvis featured a high ilium. The femur measured 107 cm in the holotype.

Its forelimbs were exceptionally robust, featuring a massive, curved thumb claw reaching 19 centimetres in length, a trait it shared with its close relative, Baryonyx. Taxonomically, Suchomimus has sparked significant debate. While some researchers have suggested it is a synonym of the European Baryonyx or the fragmentary Cristatusaurus, most modern studies treat it as a distinct genus. Recent phylogenetic analyses have even placed it within a specific tribe, Ceratosuchopsini, within the broader Spinosauridae family. This distinction matters because it helps scientists map the evolution of spinosaurids, distinguishing those with 'spinosaurine' traits, like the tall sail of Spinosaurus, from the 'baryonychinae' lineage to which Suchomimus belongs. The genus was originally assigned to the subfamily Baryonychinae. Some researchers previously proposed the family Baryonychidae. A 2017 review suggested this debate was mostly semantic. The holotype is currently kept in Niamey.

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