Baurusuchidae

These were old crocodile kinds.

They lived on land long ago. They lived in places like South America and Asia.

These animals had very deep snouts. Their teeth were sharp and had tiny ridges. These ridges helped them eat meat.

They had a special tooth in their lower jaw. This tooth fit into a notch in their upper jaw. It worked like a lock.

Some fossils show their eggs too. The egg shells were very thin. The babies had to break out of them.

It is fun to learn about these old hunters!

Baurusuchidae is a family of ancient crocodile kinds.

These animals lived a long time ago during the Late Cretaceous. Most lived on land in South America. Some lived in Asia.

These hunters had very special bodies. They had deep snouts. Their teeth were ziphodont. This means their teeth were thin and had tiny ridges. These ridges helped them eat meat. They also had a large tooth in their lower jaw. This tooth fit into a notch in the upper jaw.

Scientists have found many different kinds in this group. One is called Baurusuchus. It is the animal the family was named after. Other kinds include Pissarrachampsa and Wargosuchus. Some fossils are just small pieces. Others are more complete.

We even found fossil eggs in Brazil. These eggs were long and had blunt ends. The shells were very thin. In living crocodiles, shells often get soft to help babies hatch. But these shells stayed thin. The babies likely had to break through the shells to get out.

Caption: The skull of Pissarrachampsa.

Baurusuchidae is a family of ancient, meat-eating crocodilians. These animals lived a long time ago during the Late Cretaceous period. Most of them lived on land rather than in the water. They can be found in fossils from South America, specifically in Brazil and Argentina. Some fossils have even been found in Asia, in a place called Pakistan.

These hunters had very special bodies that helped them live on land. They had deep snouts and a curved row of teeth. Their teeth were ziphodont, which means they were thin and had tiny ridges. These ridges helped them eat meat. They also had a large tooth in their lower jaw. This big tooth fit into a deep notch in the upper jaw. A special groove was also found on their lower jaw.

Scientists have spent many years studying these creatures. A Brazilian paleontologist named Llewellyn Ivor Price named the family in 1945. He named it after a genus called Baurusuchus. In 1896, an English paleontologist named Arthur Smith Woodward named Cynodontosuchus. This was the first known member of the family, though it was only recently moved into this group. Other scientists like Edwin Harris Colbert also helped group these animals together.

There are many different types, or genera, in this family. Baurusuchus is the most famous one. Other names include Campinasuchus, Pissarrachampsa, and Stratiotosuchus. Some fossils are only small pieces, like those of Wargosuchus. The genus Pabwehshi was once thought to be a member, but it was later moved to a different group. Scientists divide the family into two groups called subfamilies: Baurusuchinae and Pissarrachampsinae.

We can even learn how they grew from fossilized eggs. In the Adamantina Formation of Brazil, scientists found eggs that likely belonged to Baurusuchus. These eggs were called Bauruoolithus fragilis. They were about twice as long as they were wide and had blunt ends. The shells were very thin, only about a quarter of a millimeter thick. In modern crocodiles, shells often get soft to help babies hatch. However, these ancient shells stayed thin, so the babies likely had to break through them to be born.

Baurusuchidae is a family of extinct, terrestrial crocodyliforms. These animals lived during the Late Cretaceous period. They were hypercarnivorous, which means they were specialized meat-eaters. Most baurusuchids lived on land rather than in the water. Their fossils have been found in South America, specifically in Argentina and Brazil. Some remains have also been found in Pakistan, in Asia.

These ancient hunters had very specific physical traits. They possessed deep snouts and a curved row of teeth. Their teeth were ziphodont, meaning they were laterally compressed and serrated. This shape helped them process meat effectively. They also had an enlarged, canine-like tooth in the lower jaw. This large tooth fit into a deep notch in the upper jaw. A distinct groove was also present on the lower jaw.

Scientists divide the family into two main subfamilies. The first is Baurusuchinae, which includes genera like Baurusuchus and Stratiotosuchus. The second is Pissarrachampsinae, which includes Pissarrachampsa and Wargosuchus. The genus Cynodontosuchus is considered the most basal member of the family. This means it is the most distantly related to the other members. Some scientists believe Cynodontosuchus might actually be a juvenile form of Wargosuchus.

Research into these animals has evolved significantly over time. Brazilian paleontologist Llewellyn Ivor Price named the family in 1945. He named it after the genus Baurusuchus. Earlier, in 1896, Arthur Smith Woodward named Cynodontosuchus. Although it was named long ago, it was only recently assigned to Baurusuchidae. Other genera like Stratiotosuchus were assigned to the family in 2001. The genus Campinasuchus was added in May 2011.

Understanding where baurusuchids fit in history is a complex task. They are part of the larger group Metasuchia. This group includes the Notosuchia, which are mostly land-dwelling crocodyliforms. It also includes the Neosuchia, which contains modern crocodiles. For a time, scientists grouped baurusuchids with Sebecidae in a group called Sebecosuchia. Recent studies have placed Baurusuchus deep within the Notosuchia group. This helps clarify how these land-dwellers relate to modern aquatic species.

There are different ways to define these biological groups. Baurusuchidae is a node-based clade. This means it includes the most recent common ancestor of Cynodontosuchus, Pissarrachampsa, and Baurusuchus. It also includes all of their descendants. Scientists also use the term Baurusuchia, which is a stem-based taxon. This group is more inclusive than Baurusuchidae. It includes all forms more closely related to baurusuchids than to other crocodyliforms. Currently, the two groups are almost identical in scope.

We can learn about their lives from fossilized eggs. In the Adamantina Formation of Brazil, scientists found eggs likely laid by Baurusuchus. These eggs belong to a species named Bauruoolithus fragilis. The eggs are about twice as long as they are wide. They have blunt ends and very thin shells. The shells are only about a quarter of a millimeter thick. These thin shells suggest how the animals hatched.

In modern crocodiles, eggshells often undergo extrinsic degradation. This process makes the shells soft so hatchlings can break through easily. However, the baurusuchid fossils do not show this degradation. This indicates that the hatchlings probably had to break through the thin shells themselves. This discovery provides a glimpse into the early life of these terrestrial predators. It shows how their development differed from the crocodiles we see today.