Rostrovenator rostrus
quadracius urioportus was a wyvernsaur notable for beginning a predatory diving niche. Rostrovenator rostrus has taken this even further, spending most of its entire life in the water and raising its young in the ocean. It can dive up to 30 meters in depth.
Its wings have reduced in size and, along with its paddle-like feet, act as flippers for steering. The legs and tail are now used for swimming. The 150 centimeter body of Rostrovenator rostrus is too large to support flight, but allows it to take a much-needed niche as a formidable predator. Countershading of the feathers also helps to be less visible to its prey items.
Rostrovenator rostrus has a visibly larger "snout." This feature started out in males, who seemed larger and more attractive with these, but it spread to females as it supports an extra air sac in the nasal system that allows more oxygen to be stored for longer dives. A reflex that lowers the heartbeat underwater also allows for oxygen to be used up more slowly. This allows for Rostrovenator rostrus to hold its breath for up to five minutes at a time and still be comfortable.does not single out and hunt the smallest individual musculates, but rather hunts larger targets such as Macrognathusensis geliniensis and schooling types like Suboslontus communis. However, Rostrovenator rostrus is not afraid to use its more robust face for grabbing unfortunate sea wyverns from the surface of the water in the species Aquadracius thalassomoloch, Aquadracius neofoundus, and smaller individuals in Aquadracius urioportus, and dragging them into the depths of the ocean to become its food.
Rostrovenator rostrus males have brighter orange skin than females as a result of sexual selection, showing that they put enough energy into their features to be fit. When a female approves, they use internal fertilization at the surface of the water where both of them can breathe. Females are the sole caretakers of offspring. A strange mutation affecting the functioning of the uterus allows the female to hold one single egg in her body longer, and she 'beaches' herself onto a beach shore and finally lays her egg within a day of it hatching, carrying it between her feet to protect it and keep it from being washed away. When the egg hatches, the mother escorts her chick into the waters and is extremely protective of it, allowing nobody near it. She will teach her chick to hunt and swim, and they will typically separate after some ten weeks of growth and care.