Ubiquitous to Spec's coasts and seas, the hesperornithines are the last of the basal Ornithuromorpha. "Hespies", as they are commonly called, were the first dinosaurs to successfully enter the marine niches in a big way. They are known from early Cretaceous deposits, some of the fossils indicating flightlessness having independently evolved several times. Having entered the seas for good, hespies seem to have only returned to land to breed and lay eggs.