Amargasuchus

• Neuquén, Argentina (La Amarga Formation)

• Amargasuchus minor

Amargasuchus is an extinct genus of the group of Mesoeucrocodylia, which dates from the Lower Cretaceous of Argentina. The Mesoeucrocodylia include today's crocodiles and various crocodile -like groups; the systematic position of Amargasuchus within the Mesoeucrocodylia is unclear. So far, only a fragmentary upper jaw is only known that originates from the La Amarga Formation and can be dated to the Lower Barremian. The only way is Amargasuchus minor.

Features

Amargasuchus was a small crocodile. The resulting section of the upper jaw measures a length of 4.16 cm, the head would have shown all have a length of about 9 to 10 cm. The snout was narrow and showed a moderate height, the bottom of the upper jaw was straight. Amargasuchus had a Antorbitalfenster, one located in front of the eye additional cranial window, which is typical for representatives of archosaurs, in today's crocodiles but missing. The preserved section of the maxilla has 13 alveoli (alveoli ), the teeth themselves are not preserved. From the shape of alveoli nevertheless shows that the teeth were laterally flattened. The teeth were equivalent in size, greatly enlarged ( hypertrophic ) were missing teeth.

System

In his first description associated Luis Chiappe (1988 ) Amargasuchus the Trematochampsidae to a group within the Mesoeucrocodylia which will include the genera Trematochampsa and Hamadasuchus attributed. Diego Pol and Zulma Gasparini (2007) noted, however, that the Trematochampsidae a problematic and insufficiently defined group are, and that current evidence would not be sufficient to safely assign Amargasuchus this group can. Instead, these researchers Amargasuchus classified as not classifiable representatives of Mesoeucrocodylia ( incertae sedis Mesoeucrocodylia ) and thus relinquish a more accurate classification of this genus.

Fund history

The find was discovered in 1984 by an expedition under the leadership of José Bonaparte. He found himself along with the skeleton of the sauropod dinosaur Amargasaurus. The site is located about 70 km south of the Argentine province of Neuquen in Zapala. The Fund ( holotype, specimen number MACN -N -12) is preserved in the collection of the Museo Argentino de Ciencias Naturales Bernardino Rivadavia in Buenos Aires.

The name Amargasuchus has the La Amarga Formation, from which comes the Fund. The second part of the species name, minor, has the small size of the crocodile.

Documents

• Extinct reptile
• Crurotarsi
• Crurotarsi ( archosaurs )