Unusual among crocodyliforms, Sebecus has a deep, narrow snout.
The nares, or nostrils, open anteriorly at the tip of the snout.
While most crocodilians have flat skulls that are raised near the eyes and postorbital region behind the eyes, the skull of Sebecus is essentially level.
The great depth of the snout makes most of the length of its upper margin level with the margin of the orbits, or eye sockets.
The supratemporal fenestrae, two holes on the skull table, are relatively small.

Laterally compressed, or ziphodont teeth, are characteristic of Sebecus and other sebecosuchians.
Although the teeth vary in size, they are homodont, having a similar shape throughout the jaw.
At the tips of the upper and lower jaws, the teeth are rounder in cross-section.
The fourth dentary tooth is raised in the lower jaw to form an effective canine.
The foremost teeth of the lower jaw are much smaller and lower than the fourth tooth.
At the tip of the jaw the first dentary tooth is procumbent, or directed forward.
The teeth of the upper and lower jaws form an alternate pattern to allow the jaw to close tightly.
A notch is present between the maxilla and premaxilla bones of the upper jaw, accommodating the fourth dentary tooth when the jaw is closed.
The procumbent first dentary teeth fit between the first and second premaxillary teeth.
This close fit allows the serrated edges of the teeth shear with one another.

The articulation between the articular and quadrate bones at the jaw joint is well developed.
Along with the broad downturned "wings" formed by the pterygoid and ectopterygoid bones at the bottom of the skull, this articulation restricts the jaw to up-and-down movement.
The jaw movement and close shearing of the teeth suggest that Sebecus was carnivorous.
Its compressed, blade-like teeth would have been well-suited for cutting meat.
In contrast, living crocodilians have circular, widely spaced teeth and usually consume their food in large pieces.
Sebecus likely consumed food in a manner more similar to theropod dinosaurs than living crocodilians.
In particular, the teeth of tyrannosaurids bear the closest resemblance to those of Sebecus.
Both animals have serrated teeth with rounded projections called denticles, and sharp clefts between the denticles called diaphyses.
These diaphyses compress meat fibers between the serrations and rip them apart.
Ultrastructural analyses using electron microscopes have revealed microwear scratches on the teeth that are suggestive of this form of cutting.

Colbert's monograph on Sebecus included a description of the brain, Eustachian tubes, and jaw musculature.
Details of these soft tissues were inferred from characteristics of the skull and endocasts, or molds of its interior.
The deep snout of Sebecus makes the shape of its brain somewhat different from those of living crocodiles, although its structure is the same.
The olfactory bulb is elongate and makes up a significant portion of the brain.
The cerebrum is narrow and long in comparison to crocodilians, and tapers toward the olfactory bulb.
The temporal lobes are somewhat smaller than those of living crocodilians.
Colbert interpreted the smaller cerebrum of Sebecus as a sign of primitiveness, with an evolutionary trend toward larger brain size in crocodilians.
Hans C. E. Larsson performed a 2001 study of the endocranial anatomy of the dinosaur Carcharodontosaurus saharicus, comparing the ratio of its cerebrum to its total brain volume to the ratios of other prehistoric reptiles.
Larsson found that Sebecus and Allosaurus fragilis had similar ratios to C. saharicus, falling within the 95% confidence range characterizing living reptile species.

The Eustachian tubes, passages that connect the middle ear with the pharynx, are very complex in crocodilians.
Unlike those of other vertebrates, the tubes are made of several interconnected branches.
This branching is fully developed in Sebecus, and probably appeared much earlier in crocodylomorphs.

The jaw muscles of Sebecus were likely similar to those of living crocodilians, but the distinctively deep
Unusual among crocodyliforms, Sebecus has a deep, narrow snout. The nares, or nostrils, open anteriorly at the tip of the snout. While most crocodilians have flat skulls that are raised near the eyes and postorbital region behind the eyes, the skull of Sebecus is essentially level. The great depth of the snout makes most of the length of its upper margin level with the margin of the orbits, or eye sockets. The supratemporal fenestrae, two holes on the skull table, are relatively small.
Laterally compressed, or ziphodont teeth, are characteristic of Sebecus and other sebecosuchians. Although the teeth vary in size, they are homodont, having a similar shape throughout the jaw. At the tips of the upper and lower jaws, the teeth are rounder in cross-section. The fourth dentary tooth is raised in the lower jaw to form an effective canine. The foremost teeth of the lower jaw are much smaller and lower than the fourth tooth. At the tip of the jaw the first dentary tooth is procumbent, or directed forward. The teeth of the upper and lower jaws form an alternate pattern to allow the jaw to close tightly. A notch is present between the maxilla and premaxilla bones of the upper jaw, accommodating the fourth dentary tooth when the jaw is closed. The procumbent first dentary teeth fit between the first and second premaxillary teeth. This close fit allows the serrated edges of the teeth shear with one another.
The articulation between the articular and quadrate bones at the jaw joint is well developed. Along with the broad downturned "wings" formed by the pterygoid and ectopterygoid bones at the bottom of the skull, this articulation restricts the jaw to up-and-down movement. The jaw movement and close shearing of the teeth suggest that Sebecus was carnivorous. Its compressed, blade-like teeth would have been well-suited for cutting meat. In contrast, living crocodilians have circular, widely spaced teeth and usually consume their food in large pieces. Sebecus likely consumed food in a manner more similar to theropod dinosaurs than living crocodilians. In particular, the teeth of tyrannosaurids bear the closest resemblance to those of Sebecus. Both animals have serrated teeth with rounded projections called denticles, and sharp clefts between the denticles called diaphyses. These diaphyses compress meat fibers between the serrations and rip them apart. Ultrastructural analyses using electron microscopes have revealed microwear scratches on the teeth that are suggestive of this form of cutting.
Colbert's monograph on Sebecus included a description of the brain, Eustachian tubes, and jaw musculature. Details of these soft tissues were inferred from characteristics of the skull and endocasts, or molds of its interior. The deep snout of Sebecus makes the shape of its brain somewhat different from those of living crocodiles, although its structure is the same. The olfactory bulb is elongate and makes up a significant portion of the brain. The cerebrum is narrow and long in comparison to crocodilians, and tapers toward the olfactory bulb. The temporal lobes are somewhat smaller than those of living crocodilians. Colbert interpreted the smaller cerebrum of Sebecus as a sign of primitiveness, with an evolutionary trend toward larger brain size in crocodilians. Hans C. E. Larsson performed a 2001 study of the endocranial anatomy of the dinosaur Carcharodontosaurus saharicus, comparing the ratio of its cerebrum to its total brain volume to the ratios of other prehistoric reptiles. Larsson found that Sebecus and Allosaurus fragilis had similar ratios to C. saharicus, falling within the 95% confidence range characterizing living reptile species.
The Eustachian tubes, passages that connect the middle ear with the pharynx, are very complex in crocodilians. Unlike those of other vertebrates, the tubes are made of several interconnected branches. This branching is fully developed in Sebecus, and probably appeared much earlier in crocodylomorphs.
The jaw muscles of Sebecus were likely similar to those of living crocodilians, but the distinctively deep
Sebecus