I am always amazed when I see a bird dive into the water, only to emerge moments later, flying again with a prize fish dinner secured in its beak. The two things, birds and the water, seem opposed to me.
So imagine how I feel reading report after report that the frighteningly enormous theropod Spinosaurus (infamous star of Jurassic Park 3 alongside Sam Neill) was basically the duck of the dinosaurs.
The latest research published here describes a Moroccan fossil bed chock full of Spinosaurus teeth mingling with the pearly whites of…sawfish!
In fact, there are little to no remains of any terrestrial dinosaurs in this bed apart from a lone, broken Carcharodontosaurus tooth, an allosauroid. The top minds here at DinoPit have wildly speculated the Carcharodontosaurus got scrappy with Spinosaurus, which retreated back into it’s watery home, shedding the broken tooth lodged in it’s hide.
But enough wild speculation! What are the facts?
The relative abundances of dental remains for the two distinct stratigraphic intervals collected at Tarda reveals that teeth of Spinosaurus occur in high abundance at both levels, but are exceptionally abundant at Site 1 where they constitute 48% of the dental remains. We know of no other dinosaur-bearing bone bed where such an abundance of dinosaur teeth occurs. The enhanced abundance of Spinosaurus teeth relative to other dinosaurs is likely a reflection of their aquatic lifestyle. An animal living much of its life in water is much more likely to contribute teeth to the river deposit than those dinosaurs that perhaps only visit the river for drinking and more casual feeding on its banks, or the occasional carcass of a terrestrial dinosaur decomposing in the river.
Thomas Beevor, Aaron Quigley, Roy E. Smith, Robert S.H. Smyth, Nizar Ibrahim, Samir Zouhri, David M. Martill,
Taphonomic evidence supports an aquatic lifestyle for Spinosaurus (Emphasis DinoPit’s)
Other Recent Discoveries Support The Aquatic Spinosaurus
Of course, this is just the latest study that throws the Spino in Mezozoic waters. Just last April, another study published by Nature described “unambiguous evidence for an aquatic propulsive structure” in a dinosaur. Essentially, it’s tail was made for swimming thanks to the obscenely tall neural spines and elongate chevrons, forming a large, flexible fin-like tail.
Thanks to computer modelling and comparisons to extant species, such as eels, we can confidently say this creature would be very good at swimming.
And even that is a discovery piled onto another analysis from 2014 describing adaptations shown by Spinosaurus compared to it’s terrestrial brethren: a nose retracted to the mid-region of the skull, solid, stocky limbs for buoyancy, and an elongated neck and trunk that shifts it’s center of mass, kinda like Micheal Phelps.
At this point, it seems almost 100% certain this gigantic theropod was built for water work. Of course, we don’t have a literal time machine to go back and look. But all of these suppositions are rigorously deduced from how remains of the Spinosaurus looks and where we find it. If it didn’t swim, why does everything point to that? If it didn’t like the water, why would it spend most of it’s life shedding teeth in a particular riverbed?
It’s as they say. If it looks like a duck, quacks like a duck, and swims like a duck, it’s probably a dinosaur in the water.