These Theropods were 6 metre long and twice the height of a man. They had tan coloured snake-like skin and a row of sharp teeth in their mouth. They appeared to attack nearly anything that moved, preferring to target their prey's soft abdomens.
Danny Quinn and James Lester from the Anomaly Research Centre arrived to investigate the suspicious activity. At the lodge they stayed at, the Eustreptospondylus entered the building and attacked the pair and Ranger Sophie. Fortunately the local Lion pride arrived to fight the opposing predator, allowing the others to escape. Two Lions were killed and the two others retreated. Lester called Connor Temple who identified the dinosaur as a Euststreptospondylus.
Later that night, the dinosaur attacked some Hippopotamus, and bit one however the hippo did not take much damage. The Eustreptospondylus then attacked the team once more, but a Postosuchus interfered and battled the dinosaur, killing it. The remains of the theropod were found later.
Watch's official series summary stated that a Eustreptospondylus would appear in Episode 5.2, though when the previews were released, only a swimming theropod was seen. It strongly resembled a black Raptor, rather than a Eustreptospondylus.
Eustreptospondylus was only the height of a man not twice the height.
The theropod was most likely a scavenger due to the vast inland oceans in the Jurassic not a hunter as presented in Primeval.