Ostafrikasaurus crassiserratus is a medium sized spinosaurid from Jurassic Africa.This spinosaur was found in Tendaguru, southeastern Africa 2012. Ostafrikasaurus lived in the Jurassic period 149 million years ago. It is known from a single isolated tooth. No one has found a full skeleton yet, but scientists estimate the whole skeleton would be up to 10.3 metres long and it would weigh about 2-3 tons. It may have had a small to medium sized sail running down the length of its back to the start of its tail and a snout reminiscent of crocodiles today.
This spinosaur would be piscivorous in real life due to its cone shaped teeth. This means that it would mainly eat fish like grizzly bears today. It also may have used it claws in much the same way to aid in catching fish. This lifestyle would mean that it would always spend its time in and around large bodies of water with a sustainable population of fish. Since there was no other large carnivores doing this as well (save for other Ostafrikasaurus) this carnivore would more than likely have flourished in its time in the late jurassic.
Ostafrikasaurus may have been one of the earliest spinosaurs to have evolved. This would result in it having very megalosaurid-like features like a shortened snout, minimized arms and small sail. The purpose of this sail so early in spinosaur evolution is unknown but it may have been used to attract a mate, help expel excess body heat to cool down, warn off bigger predators or help recognise other members of its species. Its name comes from Deutsch-Ostafrika (or German East Africa, a German colony in East Africa, which included what are now Burundi, Rwanda and Tanganyika) in which the holotype was found, from the Greekσαῦρος, sauros meaning "lizard". The specific name is derived from the Latin crassus, meaning "thick" and serratus, "serrated" in reference to the shape of the holotype tooth.