Baryonyx's sharp, curved thumb-claw resembled the strong hook on a fisherman's gaff (a tool used to lift heavy fishes out of water). This fossil (right) was reconstructed from fragments that fell out of a large, hard siltstone nodule struck by fossil hunter William Walker's geological hammer. Together with its sheath, the claw must have measured 35cm (about 14in).
dinosaur - the best preserved of any dating from its time (around 120 million years ago). The most unusual features of Baryonyx were its long, narrow, crocodile-like jaws filled with sharp teeth. It also had a longer, straighter neck than most big theropods and strong arms and hind limbs; its body was balanced by a stiffened tall.
Baryonyx's homeland was the warm floodplain that stretched from where London now stands, south into France and Belgium. The carnivorous predator prowled through conifer and cycad forests, ferny glades, and horsetail meadows fringing rivers, lakes, and swamps. It probably waded into water and caught big fishes with its great thumb-claws, much as grizzly bears snatch salmon from Alaskan rivers. Or it might have crouched on the shore, its long neck craned out just above the water, seizing passing fishes in its jaws.
The long mouth and narrow, pointed teeth would have been ideal for gripping slippery prey. Half-digested fish scales found in Baryonyx's ribcage prove that fish of roughly lm (about 3ft) in length formed at least part of this creature's diet.
However, it has been pointed out that no present-day large land animal eats only fishes, and one scientist has therefore surmised that Baryonyx also hunted terrestrial prey. Another possibility is that Baryonyx scavenged meat from the corpses of dinosaurs it found already dead, probing deep inside the carcasses with its long, narrow, sharp-toothed jaws.
Location: England, Niger
Diet: Fishes, Carrion
Size: Length 10.5m (34 ft)
Weight 2 tonnes
Classification:
Family Baryonychidae
Infraorder Tetanurae
Suborder Theropoda
Order Saurischia
Time (million years ago): 120