Phytosaurs

Introduction

Phytosaurs are an extinct group of semi-aquatic reptiles that were heavily armored. They were alive around the Late Triassic Period around 200-290 million years ago. These animals were not dinosaurs, even though the name sounds similar. Rather, archosaurs are a group of reptiles such as crocodiles and pterosaurs which are flying reptiles. The phytosaur is found across North America, Asia, Europe, northern Africa, and Madagascar. No fossils have been located in Australia, Antarctica, or sub-Saharan Africa.

Description & Size

These creatures resembled crocodiles and walked on land and swam in the water, making them semi-aquatic. Like crocodiles, the phytosaur had thick armor on their body along with rows of bony armor on their backs. The phytosaur had sharp teeth that they used to catch fish and had long, pointed jaws. They had high crested nostrils that sat in front of their eyes. These allowed them to breathe and see over the waterline when they float in it, much like a crocodile.

Phytosaurs have similar habits to crocodiles. This is due to their similar appearance. Presumably, they have the same fleshy palate that crocodiles have. The phytosaur is unable to breathe when their mouth is full of water.

The phytosaurs reached a maximum length of 35 feet. It is possible that they grew smaller or larger than that depending on the species. So far, there are only two discoverable phytosaur species. One discovered with a long snout (dolichorostral), and another with a broader snout (brachyrostral).

Diet – What Did Phytosaurs Eat?

Although the name phytosaur means “plant lizard”, they did not eat plants, but rather ate a carnivore diet. They are heterodonts, which means that they have prominent fangs, and the back teeth are sharp. These teeth enabled them to slice through their prey. The phytosaur preyed on animals that came near the water. They would wait with their protruding eyes and nostrils from the water’s surface waiting to strike.

Believably, these reptiles ate fish and other fast aquatic prey. The dolichorostral phytosaurs has a long snout that is for catching this type of prey. The broad-snouted brachyrostral phytosaur was great for hunting terrestrial prey.

Fossilized tooth evidence of the different phytosaur species showed that they either ate a piscivore or carnivore diet. They consumed either hard or soft invertebrates depending on the species’ teeth and jaw structure.

Habitat – When and Where It lived

Most phytosaurs lived a semi-aquatic lifestyle, meaning that they would come and go from water to land. The Nicrosaurus species seems to be more evolved to a terrestrial lifestyle than the others. Though all species of the phytosaur were first thought to be aquatic.

The Nicrosaurus had more developed limbs that were loner. Also possessing a deep-set upper jaw that allowed them to be efficient terrestrial hunters. Most dolichorostral types of phytosaurs did best in marine environments. Fossil evidence showed that the bones of a Mystriosuchus planirostris found in a marine setting died in either the sea or freshwater environment.

The fossils showed they had limbs that helped them paddle in the water. This would make them less adapted to walking on land for long. The tail was also compressed which is believed to have helped the creature propel itself through the water and make it a good swimmer. The majority of phytosaurs were semi-aquatic, but most species spent more time in the water than others.

Threats And Predators

The phytosaur was a predator itself that preyed on other terrestrial or aquatic creatures. They are thought to have been ambush predators that hunted animals that came down to the river to drink. The exact predators and threats that these creatures faced are unknown, but we do know that their heavily armored bodies kept them safe from most attacks by predators.

Discoveries and Fossils

The phytosaur fossils are some of the most abundant vertebrate fossils in the Petrified Forest National Park located in Arizona. The first fossil of the phytosaur is unknown. The mud-caked teeth causes researchers to believe that the phytosaur was a plant eater, but later known to be false. G. Jaeger made this discovery in 1828. The old name “phytosauria” was described by a German paleontologist named Hermann von Meyer back in 1861.

The other species of phytosaurs were described by Hermann von Meyer and Plieninger in 1844, along with Thomas Huxley’s discovery of the Indian species in 1875. This led to the generic name for the reptile being phytosaur, and evidence showed that their sharp teeth and prominent fangs were an indication that the phytosaur was not a herbivore according to the first discovery in 1828, but rather an indication of a carnivore diet.

The phytosaur fossils were discovered in India, Europe, North America, Thailand, Brazil, Madagascar, and Greenland where they were found in early Jurassic rocks, which makes it possible that they extended their range beyond the Triassic-Jurassic boundaries.

The first crocodile-like fossils of the phytosaur discovered in southern Africa were in South Africa, Zimbabwe by Steve Edwards who brought the discovery to Professor Paul Barret, and his American colleagues. This newly discovered evidence of phytosaur fossils shows that these creatures might be more widely distributed than scientists and researchers first believed.

Extinction – When Did It Die Out?

The phytosaur lived during the Late Triassic Period over 200 million years ago which is during the Carnian age. They are believed to have evolved from a crurotarsan ancestor and went extinct at the end of the Triassic. There is a hypothesis that the end-Triassic mass extinction 200 million years ago caused mass deaths in marine reefs and North American vertebrates such as the phytosaur.

Some other hypotheses of the phytosaur’s death include meteorites, global warming, rising sea levels, and even global cooling. There has been no scientific evidence yet to prove these theories, but the phytosaur did not make it out of the Triassic period like many other extinct creatures.

The Triassic-Jurassic extinction killed off around 76% of marine and terrestrial species, ending around 20% of all taxonomic families. The mass extinctions responsible for the phytosaur and many other creatures’ demise could have also been widespread volcanic activity found by scientists around the same time these creatures went extinct.

Similar Animals to The Phytosaur

There are few animals that resemble or have physical similarities to the phytosaur, but here are a few modern and extinct creatures that have exceptionally strong similarities to these reptiles.

• Crocodiles- They share a similar body structure and lifestyle to the phytosaur.
• Pterosaurs (extinct)- The earliest evolved vertebrates known to have evolved to have the ability to fly with wings.  
• Dinosaurs (extinct)- Phytosaurs were alive at the same time as dinosaurs when they were still small and evolving, so there is a slight relation between the two creatures.