Congosaurus is an extinct genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of dyrosaurid

Dyrosauridae

Dyrosauridae is a family of extinct neosuchian crocodyliforms that lived from the Late Cretaceous to the Eocene. Fossils of this group have been found in almost every continent, specifically Africa, Asia, Europe, North America and South America....

 mesoeucrocodylia

Mesoeucrocodylia

Mesoeucrocodylia is the name of the clade that includes Eusuchia and the paraphyletic group Mesosuchia. The group appeared during the Early Jurassic, and continues to the present day....

n. Fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s have been found from Angola

Angola

Angola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...

 and date back to the Paleocene

Paleocene

The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...

 epoch. In 1952 and 1964 Congosaurus was proposed to be synonymous

Synonym (taxonomy)

In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

 with Dyrosaurus

Dyrosaurus

Dyrosaurus was an extinct genus of dyrosaurid crocodyliform from the Eocene of North Africa. The type species D. phosphaticus possessed slender jaws with numerous recurved teeth, indicative of a primarily fish diet...

. The genus was later regarded to be synonymous with Hyposaurus

Hyposaurus

Hyposaurus is a genus of extinct dyrosaurid crocodyliform. Fossils have been found in Paleocene aged rocks of the Maria Farinha Formation in Pernambuco, Brazil and Iullemmeden Basin in West Africa and Maastrichtian strata in New Jersey. It was related to Dyrosaurus....

in 1976 and 1980. It has since been proven to be a distinct genus of dyrosaurid separate from both Dyrosaurus and Hyposaurus.

In 2007 a new species of Congosaurus was constructed after previously being assigned to Rhabdognathus

Rhabdognathus

Rhabdognathus is an extinct genus of dyrosaurid crocodylomorph. It is known from rocks dating to the Paleocene epoch from western Africa, and specimens dating back to the Maastrichtian era were identified in 2008. It was named by Swinton in 1930 for a lower jaw fragment from Nigeria. The type...

, and named C. compressus, extending the geographic range of the genus into the present-day Sahara

Sahara

The Sahara is the world's second largest desert, after Antarctica. At over , it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean...

. Lateromedially compressed teeth show its close relation to C. bequaerti.