Bohaiornithidae of sexual dimorphism, with the feathers being used by male members of a species for courtship display. A subadult specimen of an indeterminate bohaiornithid described in 2017 preserved feathers on various parts of the head and body which were analyzed and determined to have been iridescent in life. A referred adult specimen of "Bohaiornis" was preserved with a several rocks concentrated in the stomach region. Rocks in the stomach of birds and other animals are often believed to be gastroliths swallowed to assist in the digestion of plant material. However, the rocks apparently swallowed by this specimen are much larger,
Physiology of dinosaurs endotherms, the larger forms could have been inertial homeotherms, or that many dinosaurs could have had intermediate metabolic rates. The earliest dinosaurs were almost certainly predators, and shared several predatory features with their nearest non-dinosaur relatives like "Lagosuchus", including: relatively large, curved, blade-like teeth in large, wide-opening jaws that closed like scissors; relatively small abdomens, as carnivores do not require large digestive systems. Later dinosaurs regarded as predators sometimes grew much larger, but retained the same set of features. Instead of chewing their food, these predators swallowed it whole. The feeding habits of ornithomimosaurs and oviraptorosaurs are a mystery: although