LATE TRIASSIC PERIOD: 222 - 215 million years ago
Phytosaurs are anything but what their name suggests. When the first phytosaur was discovered, there were petrified mud fillings in the jaw that were misidentified as herbivore teeth. Initially, it was mistakenly thought that these were plant-eating reptiles, hence the name. That could not be further from the truth. The name has stuck, however. A more accurate name has been applied called "Parasuchia" meaning 'alongside crocodiles' for their resemblance to the beasts but this name is seldom used. Phytosaurs are not considered dinosaurs but were semi-aquatic reptiles.
With their heavily armored bodies measuring up to 16 feet in length and brandishing a slender snout full of razor sharp teeth, it is no doubt these creatures were the dominant predators in the lakes, rivers and swamps of the northern hemisphere during their time. Phytosaurs were very similar to modern day crocodiles with the exception of a few features. The most obvious difference is that phytosaurs had their nostrils very high up on the head just in front of their eyes. Crocodiles have theirs at the tip of their snout. Unlike crocodiles that possess a double palate to enable them to breath despite a mouth full of water, phytosaurs lacked this feature. Nevertheless, the higher level nostrils up near the eyes would have enabled them to accomplish this same breathing ability like modern day crocodiles.
The body armor of phytosaurs was much heavier than crocodiles. They had very thick bony scutes (armor plates) on the back and even covering the throat. The belly was also supported by a separate set of abdominal ribs called gastralia later to become a common feature in many dinosaurs.
Phytosaurs are divided into two subfamilies: MYSTRIOSUCHINAE and ANGISTORHININAE. The Mystriosuchinae are the more primitive phytosaurs and include MYSTRIOSUCHUS and PARASUCHUS. The Mystriosuchinae are believed to have dined predominantly on fish based on their skull designs. They had a very long and slender skull like the gavials of today and their snout was tipped with large, hook-shaped fangs with the rest of the jaws lined with uniform conical teeth; very well-adapted for catching fish. The other group called the Angistorhininae include phytosaurs like NICROSAURUS and RUTIODON. These are characterized by their heavier build and deeper, wider jaws. Their fangs were serrated and blade-like with crushing teeth further back in the jaw, conically-shaped. Based on these features and fossil stomach contents, we know these creatures fed on much larger animals including other reptiles.
Phytosaur fossils have been found in North America, India, North Africa and Europe.