Fossil snake preserving three trophic levels and evidence for an ontogenetic dietary shift

摘要: We report a fossil snake from the middle Eocene (48 Ma) Messel Pit, in whose stomach is lizard, an insect. This second known vertebrate containing direct evidence of three trophic levels. The identified as juvenile Palaeopython fischeri on basis new characters skull; lizard Geiseltaliellus maarius, stem-basilisk; and insect, despite preserved structural colouration, could not be more precisely. G. maarius thought to have been arboreal species, but like its extant relatives may foraged occasionally ground. Another, larger specimen preserves plant remains digestive tract, suggesting that omnivory this species common individuals, Basiliscus Polychrus. A general picture ecology P. yet possible, although presence individual suggests undergone dietary shift, many boines.