Regurgitalite
Regurgitalites are the fossilized leftovers of what an animal regurgitated, such as stomach contents or a regurgitated mouthful. Modern examples include owl pellets. They are a type of bromalite, or fossil trace left by an animal’s behavior, and scientists group them into different ichnotaxa.
These fossils give clues about what extinct animals ate and how they fed, but they are rarely found because they can look like ordinary feces (coprolites) and are hard to recognize.
The word regurgitalite was coined in 1992 by Adrian Hunt. There is also a spelling regurgitalith, but that was an accidental variation. In German literature, they are sometimes called Speiballen (literally “vomit ball”). More specific terms describe particular kinds: strigilite refers to fossil owl pellets; ornithoregurgitalite is regurgitated material from birds in general; gastroregurgitalite is material regurgitated from the stomach rather than the mouth.
Distinguishing regurgitalites from coprolites often needs detailed chemical and microstructural analysis.
Marine regurgitalites are known from various Mesozoic deposits. For example:
- The Triassic Polzberg Konservat-Lagerstätte in Austria has regurgitalites with ammonoid shells and other cephalopod remains, likely from large durophagous fish such as Acrodus.
- The Jurassic Posidonienschiefer (Posidonia Shale) of Germany has regurgitalites with ichthyosaurs and fish remains, probably from large ichthyosaurs.
A notable Cretaceous example comes from the Chinle Formation in Arizona, where soft tissue of the pseudosuchian archosaur Revueltosaurus is preserved in a regurgitalite, and chemical and microstructural analysis confirmed its identity as regurgitated material.
In 2025, a 66-million-year-old regurgitalite with crinoid (sea lily) remains was found in Denmark, showing predator–prey interactions just before the end of the Cretaceous.
The oldest clear fossil owl pellets come from the Oligocene Orella Member of the White River Formation in Wyoming. Although owl pellets are common in some Quaternary cave deposits, pre-Quaternary records are rare.
The oldest avian stomach pellet dates to about 120 million years ago in the Early Cretaceous Jiufotang Formation of China, found in an enantiornithine bird. It contains fish bones and shows that pellet regurgitation was part of early bird digestion.
Regurgitalites provide direct evidence of ancient predator–prey relationships and feeding behavior that body fossils alone can’t, and they help us understand diet, hunting strategies, and digestion in extinct animals. Because regurgitated material can preserve prey items in good condition, these fossils sometimes retain soft tissues and articulated bones, offering valuable insights into ancient food webs. For example, ammonoid-bearing regurgitalites from the Triassic suggest intense durophagy and contribute to the idea of the Mesozoic Marine Revolution.
This page was last edited on 2 February 2026, at 00:14 (CET).