PABULITES: THE LEGACY OF “LEFTOVERS”

Pabulites are bromalites that provide evidence of incomplete predation. They represent food that never entered the digestive tract beyond the buccal cavity and thus are “left overs.” Evidence for entry into the buccal cavity is usually provided by dentalites. Pabulites are common, but no unique characteristic distinguishes pabulites, but they can be recognized and distinguished from other bromalites based on the possession of a combination of features: lack of discrete matrix, incomplete, body often incomplete but with obvious evidence of biological causation, representation and preservation of remaining elements are consistent with partial consumption?, some elements are articulated in their original configuration, dentalites, high degree of element representation and incomplete preservation of soft tissues. A case study involves isolated feet from Eocene and Oligocene lacustrine strata in Germany. An isolated foot of a loon from the late Oligocene Enspel site is associated with a crocodile tooth, and the taphonomy of the locality indicates minimal water movement. Eight isolated feet of multiple birds occur at the middle Eocene Messel Lagerstätte. The majority of these specimens exhibit broken leg bones with missing ends, suggesting predation by crocodilians, the only non-piscivorous carnivores preserved at Messel. Pabulites are common in western North America, and virtually all specimens preserving vertebrate dentalites represent this form of bromalite. The concept of pabulites provides a new perspective on examining fossil faunas. For example, in the Upper Jurassic Morrison Formation of western North America there has been a focus on documenting dentalites and their prevalence, but there is other evidence that could allow the recognition of pabulites and an understanding of what percentage of carcasses were subjected to predation. This could provide a different perspective on predation, scavenging, food webs, and other aspects of paleoecology of the Late Jurassic ecosystem. There is evidence that some microvertebrate accumulations are pabulites. The development of the study of pabulites requires focus and documentation – actualistic studies, documentation of new examples, re-examination of the taphonomy of faunas and the establishment of a robust descriptive and ichnotaxonomic protocol.