![\"An](\"https:\/\/cdn.sci.news\/images\/enlarge14\/image_15088e-Cryptoclidid-Plesiosaur.jpg\")
<\/a><\/p>\nAn artist\u2019s impression of a plesiosaur feeding on the sea floor. Image credit: Lente Artemieff.<\/p>\n
\u201cRegurgitalites have been recognized as such for a century, but only recently they became better understood and systematically described,\u201d Dr. Knaust said.<\/p>\n
The researcher examined regurgitalites scattered through Middle to Upper Jurassic rock layers offshore Norway.<\/p>\n
The fossils, most just a few centimeters across, were recovered from cores drilled through delta deposits near the giant Troll oil and gas field on the Horda Platform.<\/p>\n
The tightly packed mix of broken and whole shells from bivalves, tube-dwelling worms called serpulids, and crinoids \u2014 along with bits of fossilized wood \u2014 shows telltale signs of having passed through a predator\u2019s digestive system, including corroded, etched shell surfaces and a jumble of species that would never naturally occur together in one spot.<\/p>\n
What makes the material particularly puzzling is that it consists of creatures that need full ocean salinity, found in sediments deposited where a river met the sea and fresh water diluted the salt water.<\/p>\n
This mismatch means something carried the food remains from farther offshore into the shallower, brackish delta before spitting them out.<\/p>\n
Based on tooth shape, feeding style, and even preserved stomach contents from related species found elsewhere, the scientist points to a family of long-necked, small-headed plesiosaurs called Cryptoclididae as the most likely regurgitalite producers.<\/p>\n
The inferred picture is of a marine reptile that foraged along the seafloor for clams, worms, and other bottom-dwelling creatures farther out at sea, then swam toward shore to bring up what it could not digest \u2014 much as some seals and dolphins do today.<\/p>\n
\u201cThere has been a lot of research into fossilized vomit over the last decade but most of it has focused on vertebrates eating other vertebrates,\u201d Dr. Knaust said.<\/p>\n
\u201cThis is the first time that plesiosaur vomit, and the shellfish in it, have been identified, and these creatures tell us a great deal.\u201d<\/p>\n
The author formally names the new trace fossil type Vomitus, with three specific varieties distinguished by their dominant contents: one rich in bivalve shells, one dominated by serpulid worm tubes, and one made up mostly of crinoid fragments.<\/p>\n
Similar clumps had been found in isolated instances in other parts of the world over the past century, sometimes mistaken for storm deposits or misidentified fecal material, but the Norwegian specimens represent the first such fossils documented in continuous drill-core material and the first attempt to systematically classify them.<\/p>\n
\u201cThe plesiosaur is a fascinating animal,\u201d Dr. Knaust said.<\/p>\n
\u201cThese findings add to other kinds of evidence that help us to understand their abilities and behavior.\u201d<\/p>\n
\u201cAnd this is still just the beginning. There\u2019s so much more we can learn from picking through what extinct animals threw up after dinner.\u201d<\/p>\n