Integumentary remains and abdominal contents in the Early Cretaceous Chinese lizard, Yabeinosaurus (Squamata), demonstrate colour banding and a diet including crayfish

Abstract

The Early Cretaceous lizard Yabeinosaurus is well-represented in the Jehol Biota of northeast China, with specimens yielding information on ontogenetic development, reproductive strategy, and diet, as well as skeletal morphology. However, a large, well-preserved, new specimen of Yabeinosaurus robustus from the Lamadong locality, Liaoning, provides further insights into the morphology and biology of this species. Integumentary traces demonstrate that, in life, Y. robustus was coloured with well-defined light and dark banding through both the body and the tail. The integumentary traces also confirm that Yabeinosaurus was covered with thin, non-overlapping osteoderms. Previous specimens have contained fish remains, suggesting that Yabeinosaurus foraged in, or close, to the water. The new specimen supports that hypothesis as it contains the remains of a large crayfish, identified as belonging to the species Palaeocambarus licenti Taylor et al. 1999. Body parts of the crayfish provide an estimated original total length of 120–140 mm.