Shartegosuchidae Temporal range: Late Jurassic - Early Cretaceous |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Mesoeucrocodylia |
Family: |
†Shartegosuchidae Efimov, 1988 |
Genera | |
Shartegosuchidae is an extinct family of Late Jurassic and Early Cretaceous crocodylomorphs. The family is named after the Late Jurassic Shar Teeg Beds in southwestern Mongolia, from which most shartegosuchid remains have been found. Five genera are currently assigned to Shartegosuchidae: Shartegosuchus, Nominosuchus, Kyasuchus, Adzhosuchus, and Fruitachampsa. Shartegosuchus, Nominosuchus, and Adzhosuchus all come from Shar Teeg, while Kyasuchus is known from the Early Cretaceous of Russia. Fruitachampsa is known from the Late Jurassic Morrison Formation of the western United States.
Shartegosuchids are known only from cranial material, or parts of the skull. No remains of any other parts of the body have been found. Shartegosuchids share several distinct characteristics in the skull. On the palate, the choanae (holes where the nasal cavity opens into the mouth) is placed within a deep depression of its midline. The palatal bones, located behind the choanae in what is known as the secondary palate, unite with each other at the midline of the palate. Shartegosuchids can also be diagnosed by the position of the teeth in their lower jaws, which are never found behind the mandibular fenestrae (holes found near the back of the jaw). The edges of the teeth are denticulated, or ridged. The shape and position of several bones of the skull, including the frontal, nasal, lacrimal, and quadrate, are also distinctive. Unlike most other archosaurs, shartegosuchids lack an antorbital fenestra, an opening in the skull in front of the eyes.