Nathan p Myhrvold

Academic paper

Historical Biology: An International Journal of Paleobiology

24

5

505-517

Numerous extant carnivorous, piscivorous and insectivorous species � including birds, pinnipeds, varanid lizards and crocodiles and mammals � routinely ingest food combined with a high proportion of indigestible material that can be neither absorbed through digestion nor eliminated as faecal matter. Their solution is to egest the indigestible portion through the mouth as a gastric pellet. The status of gastric pellets in extant species is reviewed. Arguments based on phylogeny, anatomy and biomechanics strongly suggest that many extinct species, including crocodilians and pterosaurs, may also have produced gastric pellets routinely. The term �emetolite� is proposed for fossilised gastric pellets produced by routine emesis. Unfortunately, few reports of emetolites have been made; those specimens reported to date are reviewed. Various hypotheses may explain this negative result, the strongest being a collection bias. Because paleontologists do not expect to find them, emetolites may go unrecognised or uncollected or could be destroyed inadvertently during preparation. Emetolites would offer a valuable fossil record, and thus they warrant consideration by field paleontologists and preparators. A greater awareness of their probable characteristics may lead us to discover that they are more abundant than has been assumed.

gastric pellets; fossilised; emesis; collection bias; fossil record

English