When most people picture a crocodile, they imagine a heavy reptile resting near water, waiting for the perfect moment to strike. That image feels accurate, but it only shows a small slice of a much bigger story. Millions of years ago, some crocodile ancestors looked and behaved very differently.
These early relatives were fast, light, and built for running. They chased prey across dry land with surprising speed. Some even ran on two legs, which sounds more like a dinosaur than a crocodile. This forgotten chapter of evolution is now gaining attention, thanks to new fossil research.
Meet Galahadosuchus, the Land-Running Croc
San / Pexels / A recently identified species, ‘Galahadosuchus jonesi,’ is helping scientists rethink crocodile evolution.
These bones turned out to belong to a small but impressive predator from the Late Triassic period.
Galahadosuchus lived around 215 million years ago in what is now southwest England, according to the latest discovery. It belonged to a larger group called Crocodylomorpha, which includes all modern crocodiles and alligators. Even so, its body looked nothing like the bodies of the animals we see today. It had long legs placed directly under its body, giving it a tall, upright stance.
This posture made a big difference in how it moved. Instead of dragging itself along like modern crocodiles, it could run swiftly and in balance. Its slim frame reduced weight, which likely helped it chase prey over longer distances.
Scientists believe Galahadosuchus hunted small animals like early mammals, reptiles, and amphibians. It lived in dry, open landscapes, not near rivers or swamps. That setting required agility and endurance, and this animal had both.
The species name honors David Rhys Jones, a teacher who inspired the lead researcher. It shows how science often connects back to people who spark curiosity and passion.
Effigia and the Rise of Two-Legged Crocodiles
Galahadosuchus was not alone in this strange and exciting group. Another well-known example is Effigia, a prehistoric crocodile relative found in North America. Fossils of Effigia were discovered at Ghost Ranch in New Mexico, a site famous for its rich fossil beds.
Effigia lived around 200 million years ago, close to the end of the Triassic period. Its body was built for speed, with long legs and a lightweight structure. What really sets it apart is how it moved. Effigia ran on its two hind legs, much like certain dinosaurs.
This form of movement, called bipedal locomotion, allowed it to cover ground quickly. It likely used its speed to chase down prey in open environments. Its narrow body and long limbs made it an efficient runner, more like a racing animal than a slow reptile.
The world Effigia lived in looked very different from the one we live in today. The continents were joined into a single landmass called Pangaea. This created wide, open plains where fast movement was a clear advantage.
A Lost Era of Fast-Moving Predators
Jeff / Pexels / The Late Triassic period was full of diversity, including these fast-running crocodile relatives. For a time, they thrived in their environments.
Their speed and agility helped them compete with other predators and survive in changing conditions.
However, this success did not last forever. Around 201 million years ago, a major extinction event reshaped life on Earth. Massive volcanic eruptions released huge amounts of gas into the atmosphere. This caused rapid climate changes that many species could not survive.
Many of the land-running crocodile relatives disappeared during this event. Their specialized bodies, built for speed on land, may not have suited the new conditions. As these animals vanished, new groups began to take their place.
Dinosaurs, in particular, expanded into the open niches left behind. They became the dominant land animals for millions of years. Meanwhile, the crocodile lineage took a different path.