Primordial Predators

by AMNH on

On Exhibit posts

Crocodiles and their relatives are some of the most enduring creatures on the planet.

Ancient crocodylians dominated the landscape before the time of their cousins, the dinosaurs, and their successors have survived and thrived into the modern day. The new exhibition Crocs: Ancient Predators in a Modern World brings a variety of live crocodiles and their relatives, including alligators and dwarf crocodiles, to the Museum, where visitors can meet these primordial predators in the flesh.

Dwarf Crocodile Photo
A juvenile African dwarf crocodile.
© McDonald Wildlife Photography

Crocodiles and their relatives have assumed a wide variety of body types and shapes over their long history. Some early crocodylians, like Hesperosuchus agilis, lived on land and boasted lithe, agile builds more evocative of a modern greyhound than today’s crocodiles, while Simosuchus clarki was a pug-nosed croc that lived on land and like ate a mostly vegetarian diet. Other species, like Deinosuchus riograndensis, which was discovered by Museum paleontologist Edwin Colbert in 1954 and lived around 75 million years ago, looked more like its modern relatives, but likely reached lengths of up to 35 feet, making them much larger than modern crocs.

Artist's rendering of Simosuchus clarki
Artist’s rendering of the pug-nosed crocodylomorph Simosuchus clarki.
Image courtesy of Wikimedia Commons

While these giant crocs are long extinct, many species of crocodiles, as well as their relatives, alligators and gharials, still thrive. Species like the saltwater crocodile and American alligator loom large in the popular imagination and waterways alike, but they’re not the only examples. Smaller species like the caimans of South America and the dwarf crocodiles of Western Africa (Osteolaemus tetraspis) grow to no more than 6.5 feet (2 meters) long.

Unlike their larger relatives, which tend to live in open, fast-flowing rivers, dwarf crocodiles dwell in small freshwater streams and muddy swampland. Some have even been found living in isolated watering holes on the savanna, retreating to burrows when the rainy season ends and their habitat dries up. 

Dwarf crocodiles don’t spend as much time basking in sunshine as larger crocs and are much more likely to be seen on land at night—habits that can likely be attributed to their relatively diminutive size. While they boast the same bony plating and scale armor that makes other crocodiles so formidable, their smaller proportions mean that they are not only predators, but also occasionally prey, even when they reach adulthood. 

Saltwater Crocodile Photo
A saltwater crocodile basking on a riverbank in Australia.
Image courtesy of Paul Thomsen

It may seem strange to call an animal that can grow as long as 6.5 feet a “dwarf,” but dwarf crocodiles are puny compared to their cousins. The largest recorded example of a saltwater crocodile, for instance, was a specimen captured in the Philippines in 2012 that measured more than 20 feet long and weighed more than a ton.

A version of this story originally appeared in the Spring 2016 issue of the Member magazine Rotunda.