Regurgitating Species
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Fossilization is so rare that less than a tenth of 1% of all animal species that ever existed on Earth were lucky enough to become fossils. Finding them is even less likely, and sometimes they sit in a museum for years before anyone realizes the treasure they hide. That’s what happened at the Museu Câmara Cascudo in Brazil, where a limestone concretion from Araripe gathered dust until someone noticed it wasn’t an ordinary fossil.
Yes, it contained animal remains: slender toothed jaws, a metatarsal, a foot phalanx, some bone fragments, and, next to them, four fish. But these were only perfectly preserved hard parts, without a trace of soft tissue. More importantly, they weren’t arranged randomly but uniformly aligned. Such a compact, orderly composition could only result from a mass of indigestible material expelled quickly. That’s right: the fossilized material was dinosaur vomit!
The scientific name for this type of deposit is regurgitalite, and the uniform arrangement of the remains reflects the fact that the expelled material is wrapped in mucus, which keeps everything together and prevents elements from scattering.
But the surprises didn’t end there. The jaws—long, densely packed, comb-like structures—were analyzed and did not resemble anything known from the region. Comparing them with other pterosaurs from the same period revealed similarities, yes, but also enough differences to reach a clear conclusion: that vomit contained a new species, and moreover the first filter-feeding pterosaur ever found in Brazil.
The animal was named Bakiribu waridza, meaning “comb mouth” in the indigenous Kariri language spoken in the Araripe region of northeastern Brazil, where the fossil was found.
And what do we know about the predator? The lack of corrosion on the bones suggests that the regurgitation occurred shortly after the meal, and the ordered sequence of remains indicates it first ate two pterosaurs, then the fish, and finally vomited everything due to an obstruction caused by the pterosaur’s jaws. Who the predator was remains unknown, but one hypothesis points to a spinosaur, already known from the area and previously found with one of its teeth embedded in the neck of an ornithocheiroid pterosaur.
Thanks to this unusual digestive mishap from millions of years ago, scientists uncovered not only a new species but also one of the rare direct pieces of evidence of trophic interactions in the ancient tropical ecosystem of Araripe.
See You Soon and Good Science!
Source Drawing by Julio Lacerda
