CRETACEOUS CROCODILES OF NORTHERN BRITISH COLUMBIA

Ancient crocodile claw marks uncovered 

During the Cretaceous, giant crocodiles, nine to 12 metres in length, basked in the sun and swam in ancient lakes and rivers in what is now northern British Columbia. 

They lived alongside dinosaurs and turtles in the low-lying delta-plain, perhaps escaping the intense heat of the sun by cooling themselves in the shallow lakes, rivers, swamps and wetlands.

During the Cretaceous, their watery neighborhood was 100 kilometres inland from the shores of the Western Interior Seaway, the large inland sea which divided North America in two.

The first hint of our crocodylian friends in British Columbia's far north comes from trace fossils — swim traces of their exploits moving and scraping along muddy bottoms, along with claw marks from their clawed, webbed toes, a partial track and markings left by scale patterns from thick, plated skin. 

Ankylosaurus. Adults averaged 6 - 8 metres in length

Some of the markings record behaviour and close encounters with their neighbours. One remarkable find shows crocodile and ankylosaur tracks side-by-side — on the same slab.  

The ankylosaur tracks were smallish at 10cm wide, so perhaps left by an unlucky juvenile grazing at the waters edge who did not know the danger lurking nearby. 

If the lizard-like fellow who made the crocodylian tracks looked like his modern relatives — the largest and heaviest of present-day reptiles — then his unique body shape would have allowed his eyes, ears and nostrils to remain above the surface while his body was hidden below, affording him the perfect place to cool off and strike his prey close to the waters edge. 

We have not yet recovered the bones that would confirm this particular crocodylian's design, but they likely had powerful jaws and many conical teeth on the business end of their long, massive bodies.

The fossils were recovered from the Peace Region of northeastern British Columbia, north of Tumbler Ridge, between the Rocky Mountain Foothills on the west and the Alberta Plains on the east. The fossils found here are just a shade older than their cousin Deinosuchus but these potential precursors are on par for size.