Tuesday, November 26, 2019

Ferrisaurus: Beast of the Week

This week we will be checking out a newly described dinosaur!  Ferrisaurus sustutensis was a plant-eating dinosaur that lived in what is now British Columbia, Canada, during the late Cretaceous period, about 68 million years ago.  It was a small member of the ceratopsian group of dinosaurs, measuring just under six feet long from beak to tail.  The genus name, Ferrisaurus, translates to "Iron Reptile" in reference to the fact that its bones were found near railroad tracks.

The ceratopsian dinosaurs, known for their elaborate frills, horns and beaks, were extremely successful at the end of the Cretaceous, having diversified into many different forms.  In North America, the earliest known ceratopsian, called Aquilops, was only about the size of a housecoat, but by the latest cretaceous its lineage would diversify into many much larger forms.  Triceratops, which could grow to thirty feet long, is the most famous member of this group, but there were other ceratopsians that lived at the same time as Triceratops that were still quite small and would have occupied a different niche.  Ferrisaurus, which was about the same size as an average human, was one such example.

Life reconstruction of Ferrisaurus in watercolors by me.

Within ceratopsians, Ferrisaurus was a member of a more specific family, called Leptoceratopsidae. These smaller ceratopsians typically didn't have any long horns on their faces like their bigger relatives did, but they still had powerful curved beaks and bony frills behind their heads.  Unfortunately, Ferrisaurus' skull was never discovered, but it can be guessed that it would have looked similar to other more completely known members of this family.  Judging by the jaw proportions in known leptoceratopsid skulls, these dinosaurs would have had devastatingly powerful biting power, which they likely used to eat tough plant material, but they also could have used this as an effective weapon to ward away would be predators, despite their small size.

Photograph of the radius (lower arm bone) of Ferrisaurus on the left compared to those of other leptoceratopsids.  Photo is from the recently published paper by Dr. Victoria Arbour, which is linked below.

Ferrisaurus is unique because its front limbs were proportionally shorter to its body than those of its closest known relatives.  Also its toes were differentiating lengths to each other compared to those of other leptoceratopsids.  Another striking fact about this dinosaur is the fact that it lived in what is now British Columbia, all the way up in Western Canada, an area that is not known for having many dinosaur fossils.  The presence of Ferrisaurus gives hope that paleontologists might discover more dinosaurs in the same area one day to illustrate a better idea of the kind of life that called British Columbia home 68 million years ago!

References

Arbour, Victoria; Evans, David (2019). "A new leptoceratopsid dinosaur from Maastrichtian-aged deposits of the Sustut Basin, northern British Columbia, Canada".