Smallest ever Tylosaurus fossil sheds light on species

The smallest Tylosaurus mosasaur fossil ever found has been revealed in a new study in the Journal of Vertebrate Pale ontology and surprisingly it lacks a trademark feature of the species.The fossil, likely to be that of a newborn, does not have the recognizable long snout typically seen in the species. The lack of this snout initially perplexed researchers, who struggled to identify which group of mosasaurs it belonged to.

After examining and comparing the fossil to young specimens of closely-related species, such as T. nepaeolicus and T. proriger, which already had identifiable noses, researchers finally deemed it to be a young Tylosaurus. The lack of snout in the baby specimen found suggests to researchers that the development of this feature happens extremely quickly, between birth and juvenile stage -- something that previous studies on the species had failed to notice.